Supreme Court New South Wales Medium Neutral Citation: Insurance Australia Ltd t/as NRMA Insurance v Kirkpinar [2025] NSWSC 162 Hearing dates: 19 November 2024 Date of orders: 10 March 2025 Decision date: 10 March 2025 Jurisdiction: Common Law Before: Mitchelmore J Decision: (1) Amend the name of the second defendant by deleting the words "S7.26 of the Motor Accidents Injuries Act 2017" and replacing them with "section 63 of the Motor Accidents Compensation Act 1999 (NSW)". (2) Order in the nature of certiorari moving into this Court and quashing the certificate of determination of the second defendant dated 26 April 2024 purportedly issued pursuant to s 63(3) of the Motor Accidents Compensation Act 1999 (NSW). (3) Order that the plaintiff's application for review of the certificate of Medical Assessor Home dated 12 April 2023 is remitted to the third defendant for referral to a differently constituted review panel for determination according to law. (4) Order that the first defendant is to pay the plaintiff's costs. Catchwords: Administrative law – judicial review – review panel under the Motor Accidents Compensation Act 1999 (NSW) – approach to causation under s 58(1)(d) of the Motor Accidents Compensation Act 1999 (NSW) – adequacy of reasons – whether review panel failed to respond to substantial and clearly articulated arguments – whether review panel failed to consider and evaluate evidence before it and intellectually engage with the case before it Legislation Cited: Motor Accidents Compensation Act 1999 (NSW), ss 44, 57, 58, 60, 61, 62, 63, 122, 123, 131, 133 Motor Accident Injuries Act 2017 (NSW), s 1.8 Cases Cited: AAI Ltd t/as AAMI v Phillips [2018] NSWSC 1710; 87 MVR 20 Allianz Australia Insurance Ltd v Mackenzie [2014] NSWSC 67; 66 MVR 124 Allianz Australia Insurance Ltd v Salucci [2023] NSWSC 1593; 106 MVR 154 DNM Mining Pty Ltd v Barwick [2004] NSWCA 137 Dranichnikov v Minister for Immigration and Multicultural Affairs (2003) 77 ALJR 1088; [2003] HCA 26 Frost v Kourouche (2014) 86 NSWLR 214; [2014] NSWCA 39 Insurance Australia Group Ltd t/as NRMA Insurance v Keen (2021) 399 ALR 765; [2021] NSWCA 287 Jarvis v Allianz Australia Insurance Ltd [2022] NSWCA 232; 102 MVR 476 Jobling v Associated Dairies Ltd [1982] AC 794 K'Mart Australia Ltd v McCann [2004] NSWCA 283 LPDT v Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs (2024) 98 ALJR 610; [2024] HCA 12 Owen v Motor Accidents Authority of NSW [2012] NSWSC 650; 61 MVR 245 Rodger v De Gelder [2015] NSWCA 211; 71 MVR 514 Sadsad v NRMA Insurance Ltd [2014] NSWSC 1216; 67 MVR 601 Slade v Insurance Australia Ltd t/as NRMA [2020] NSWSC 1031; 93 MVR 378 Value Constructions Pty Ltd v Badra [2024] NSWCA 181 Wingfoot Australia Partners Pty Ltd v Kocak (2013) 252 CLR 480; [2013] HCA 43 Texts Cited: American Medical Association, Guides to the Evaluation of Permanent Impairment (Fourth Edition), third printing, 1995 State Insurance Regulatory Authority, Motor Accident Permanent Impairment Guidelines (version 1), effective 1 June 2018 Category: Principal judgment Parties: Insurance Australia Ltd t/as NRMA Insurance (Plaintiff) Musa Kirkpinar (First Defendant) Hugh Macken, Michael Couch and Drew Dixon as a review panel constituted under section 63 of the Motor Accidents Compensation Act 1999 (NSW) (Second Defendant) President of the Personal Injury Commission of New South Wales (Third Defendant) Representation: Counsel: J Gumbert (Plaintiff) D Hooke SC / DL Del Monte (First Defendant) Solicitors: Moray & Agnew (Plaintiff) Turner Freeman Lawyers (First Defendant) Crown Solicitor of NSW (Second and Third Defendants) File Number(s): 2024/216251 Publication restriction: Nil Decision under review Court or tribunal: NSW Personal Injury Commission Jurisdiction: Motor Accidents Division Date of Decision: 29 April 2024 Before: Hugh Macken, Michael Couch and Drew Dixon as a review panel under section 63 of the Motor Accidents Compensation Act 1999 (NSW) File Number(s): R-M10573891/23 JUDGMENT 1. The plaintiff, Insurance Australia Ltd t/as NRMA Insurance (NRMA), seeks judicial review of a decision of a medical review panel constituted in the Motor Accidents Division of the Personal Injury Commission (review panel). The subject of the review panel's decision was a medical assessment certificate issued on 29 November 2022 in relation to the first defendant, Musa Kirkpinar. 2. Mr Kirkpinar was injured in a motor vehicle accident in New South Wales in July 2011. NRMA was the insurer of the vehicle that was at fault. In August 2011, Mr Kirkpinar made a claim under the Motor Accidents Compensation Act 1999 (NSW) (the MAC Act). NRMA accepted liability subject to assessment of injury and damages. Subsequently, NRMA disputed whether the degree of permanent impairment as a result of injuries caused by the motor accident was greater than 10% (which is the threshold for the award of damages for non-economic loss under s 131 of the MAC Act). That dispute was about a medical assessment matter to which Part 3.4 of the MAC Act applies: s 58(1)(d). 3. Pursuant to s 60 of the MAC Act, the dispute was referred to a medical assessor, Dr T.Michael Long. On 5 May 2015, Assessor Long issued a certificate under s 61(1) of the MAC Act, determining that Mr Kirkpinar sustained soft tissue injuries to his cervical spine, lumbar spine, and hips as a result of the motor accident, giving rise to a permanent impairment which was not greater than 10%. Neither party sought to review that certificate. 4. In September 2021, Mr Kirkpinar lodged an application for referral for further medical assessment of his degree of permanent impairment. In support of that application, he relied on further treatment he had undergone for his injuries since the date of Assessor Long's certificate (5 May 2015), in particular a total left hip replacement. NRMA again disputed whether the degree of permanent impairment as a result of injuries caused by the motor accident was greater than 10%. This dispute was referred to a medical assessor, Dr Alan Home. On 12 April 2023, Assessor Home issued a certificate determining that injuries to Mr Kirkpinar's cervical spine, lumbar spine, right hip and left hip were caused by the motor accident and that the degree of permanent impairment from those injuries was 20%. 5. NRMA applied for review of that decision. It contended that Assessor Home had asked himself the wrong question in relation to causation and had incorrectly applied the Motor Accident Permanent Impairment Guidelines issued under the MAC Act. On 14 June 2023, a delegate of the third defendant referred NRMA's review application to a review panel. On 26 April 2024, the review panel issued a certificate of determination, revoking the certificate of Assessor Home and making a new certificate determining that the degree of permanent impairment was 15%. 6. The focus of NRMA's application for judicial review was the review panel's approach to causation in relation to the injury to Mr Kirkpinar's left hip and the injury to his lumbar spine, and how that was addressed in its reasons. NRMA alleged that the review panel: 1. erred in its approach to causation in relation to the left hip injury, and failed to consider and/or determine causation at all in relation to the lumbar spine injury (ground 1); 2. failed to give adequate reasons with respect to causation in relation to both of those injuries (ground 2); 3. failed to respond to the substantial and clearly articulated arguments that NRMA advanced regarding the respective causes of Mr Kirkpinar's left hip surgery and the lumbar spine injury (ground 3); and 4. failed to evaluate the available evidence as required by the guidelines issued under the MAC Act and "failed to intellectually engage with the insurer's case" (ground 4). 1. Mr Kirkpinar was the only defendant to take an active role in the proceedings, with the second and third defendants filing submitting appearances. The second defendant was described in the summons as the three individuals who constituted the review panel "under s 7.26 of the Motor Accident Injuries Act 2017 (NSW)". The reference to the Motor Accident Injuries Act is in error as that Act does not apply to a motor accident occurring before its commencement: s 1.8. Instead, and as the orders that NRMA sought in the summons correctly recognised, the review panel was convened pursuant to s 63 of the MAC Act. I will direct that the name of the second defendant be changed in this respect. 2. For the reasons set out below, the decision of the review panel was affected by jurisdictional error and, separately, error of law on the face of the record. The decision of the review panel will be set aside and the matter remitted. Background to the review panel's decision 1. The evidence in these proceedings comprised three affidavits of Julian Edward Kenda, the solicitor with carriage of the matter for NRMA, sworn on 18 July 2024, 16 August 2024 and 24 September 2024. The affidavits annexed the review panel's certificate and reasons dated 26 April 2024 together with a subset of the material that was before the review panel. 2. Before turning to the chronology of the evidence, it is useful to provide some legislative context. Assessment of permanent impairment and the Guidelines 1. Chapter 5 of the MAC Act regulates the award of damages for injury caused by the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle: s 122(1). A court cannot award damages in respect of a motor accident contrary to that chapter: s 123(1). Pursuant to s 131, damages may not be awarded for non-economic loss unless the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident is greater than 10%. Section 133 provides that the assessment of the degree of permanent impairment is to be expressed as a percentage in accordance with Pt 5.3 of the Act. The assessment is to be made in accordance with the guidelines issued for that purpose: s 133(2). 2. Part 3.4 of the MAC Act makes provision for the assessment of impairment and for resolving disputes about that assessment. Section 57 defines a "medical dispute" as "a disagreement or issue to which this Part applies". Section 58(1) provides in this respect: (1) This Part applies to a disagreement between a claimant and an insurer about any of the following matters (referred to in this Part as medical assessment matters)— (a) whether the treatment provided or to be provided to the injured person was or is reasonable and necessary in the circumstances, (b) whether any such treatment relates to the injury caused by the motor accident, (c) (Repealed) (d) whether the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident is greater than 10%. (e) (Repealed) 1. A party to a medical dispute may refer the dispute to the President of the Personal Injury Commission (PIC) for assessment under Part 3.4: s 60(1). The President is to arrange for the dispute to be referred to one or more medical assessors: s 60(2). A medical assessor to whom the dispute is referred is to give a certificate "as to the matters referred for assessment": s 61(1). The certificate is conclusive evidence "as to the matters certified" in any court proceedings or assessment by the PIC in respect of the claim concerned: s 61(2). A certificate is to set out "the reasons for any finding by the medical assessor or assessors as to any matter certified in the certificate in respect of which the certificate is conclusive evidence": s 61(9). 2. Section 44 of the MAC Act provides that "the Authority", being the State Insurance Regulatory Authority (SIRA), may issue guidelines with respect to, relevantly, "the assessment of the degree of permanent impairment of an injured person as a result of an injury caused by a motor accident": s 44(1)(c). The Motor Accident Permanent Impairment Guidelines, Version 1 (the Guidelines) apply to motor accidents that occurred between 5 October 1999 and 30 November 2017. The Introduction to the Guidelines notes that they are based on the American Medical Association's "Guides to the Evaluation of Permanent Impairment, Fourth Edition" (to which I will refer to below as "AMA4"), albeit modified "to align them with Australian clinical practice and to better suit the purposes of the MAC Act". Clause 1.2 of the Guidelines directs a medical assessor undertaking impairment assessments for the purposes of the MAC Act to read the Guidelines in conjunction with AMA4, but also states that "[t]hese Guidelines are definitive with regard to the matters they address". 3. An "impairment" is defined in cl 1.9 of the Guidelines: "Impairment is defined as an alteration to a person's health status. It is a deviation from normality in a body part or organ system and its functioning. Hence, impairment is a medical issue and is assessed by medical means." 1. Clause 1.21 of the Guidelines provides that the evaluation under the Guidelines "should only consider the impairment as it is at the time of the assessment". Clause 1.17 provides that a medical assessor is to evaluate the available evidence and be satisfied that any impairment "is an impairment arising from an injury caused by the accident" and "is an impairment as defined in clause 1.9 above". The section of the Guidelines titled "Causation of injury" provides as follows: "1.5 An assessment of the degree of permanent impairment is a medical assessment matter under Section 58 (1)(d) of the Act. The assessment must determine the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident. A determination as to whether the injured person's impairment is related to the accident in question is therefore implied in all such assessments. Medical assessors must be aware of the relevant provisions of the AMA4 Guides, as well as the common law principles that would be applied by a court (or claims assessor) in considering such issues. 1.6 Causation is defined in the Glossary at page 316 of the AMA4 Guides as follows: 'Causation means that a physical, chemical or biologic factor contributed to the occurrence of a medical condition. To decide that a factor alleged to have caused or contributed to the occurrence or worsening of a medical condition has, in fact, done so, it is necessary to verify both of the following: 1. The alleged factor could have caused or contributed to worsening of the impairment, which is a medical determination. 2. The alleged factor did cause or contribute to worsening of the impairment, which is a non-medical determination.' This, therefore, involves a medical decision and a non-medical informed judgement. 1.7 There is no simple common test of causation that is applicable to all cases, but the accepted approach involves determining whether the injury (and the associated impairment) was caused or materially contributed to by the motor accident. The motor accident does not have to be a sole cause as long as it is a contributing cause, which is more than negligible. Considering the question 'Would this injury (or impairment) have occurred if not for the accident?' may be useful in some cases, although this is not a definitive test and may be inapplicable in circumstances where there are multiple contributing causes." (Emphasis in original.) 1. The reference to "common law principles" in clause 1.5 of the Guidelines, and in earlier versions of the Guidelines, has been interpreted as "referring to the legal principles that courts or claims assessors are required to apply in determining causation" and include "not only common law principles, in the strict sense, but also such principles as modified or explained by statutory provisions, such as s 5D of the Civil Liability Act 2002 (NSW), where applicable": Slade v Insurance Australia Ltd t/as NRMA [2020] NSWSC 1031; 93 MVR 378 at [80]-[81]; Owen v Motor Accidents Authority of NSW [2012] NSWSC 650; 61 MVR 245 at [27]. 2. The Guidelines also make the following provision for pre-existing impairments: "1.31 The evaluation of the permanent impairment may be complicated by the presence of an impairment in the same region that existed before the relevant motor accident. If there is objective evidence of a pre-existing symptomatic permanent impairment in the same region at the time of the accident, then its value must be calculated and subtracted from the current WPI value. If there is no objective evidence of the pre-existing symptomatic permanent impairment, then its possible presence should be ignored. 1.32 The capacity of a medical assessor to determine a change in physical impairment will depend upon the reliability of clinical information on the pre‑existing condition. To quote the AMA4 Guides (page 10): 'For example, in apportioning a spine impairment, first the current spine impairment would be estimated, and then impairment from any pre-existing spine problem would be estimated. The estimate for the pre-existing impairment would be subtracted from that for the present impairment to account for the effects of the former. Using this approach to apportionment would require accurate information and data on both impairments.'" The motor accident and the medical dispute 1. On 16 July 2011, Mr Kirkpinar was riding a bicycle when he was struck from behind by a motor vehicle. In the claim form he submitted under the MAC Act, Mr Kirkpinar stated that as a result of the accident he suffered injuries to his right leg, left leg, the left side of his body, his left shoulder and his cervical spine. He also referred to having suffered a stroke in December 2008. 2. As I noted above, NRMA admitted liability "on the basis that injuries and damages are still to be assessed", and subsequently raised the dispute to which Part 3.4 of the MAC Act applied. Assessor Long described the scope of the dispute in his certificate dated 15 May 2015 as relating to: 1. the list of Mr Kirkpinar's injuries referred (described as "soft tissue injuries to the cervical spine, lumbar spine and hips") and whether they were each caused by the motor accident; 2. the degree of permanent impairment of Mr Kirkpinar as a result of each of the injuries referred that were found to be so caused; and 3. whether the degree of permanent impairment as a result of injuries caused by the motor accident was greater than 10%. Assessor Long's certificate 1. In the certificate and reasons that Assessor Long issued under s 61 of the MAC Act, he found that as a result of the motor accident Mr Kirkpinar sustained "soft tissue injuries to his cervical spine and lumbar spine, [and] soft tissue injuries to his hips with aggravation of pre-existing degenerative arthritis left hip and to a lesser extent the right hip". He referred to the degenerative arthritis to the left hip, which he described as "extensive", being documented before the motor accident. However, he considered that the evidence before him was not sufficient to determine a deductible proportion. Accordingly, Assessor Long did not apply a deduction for the pre-existing impairment. 2. Applying the Guidelines, Assessor Long assessed the degree of Mr Kirkpinar's whole person impairment (WPI) in relation to the cervical spine injury at 0%, and the lumbar spine injury at 0%. He assessed the WPI in relation to the right hip injury at 2%, and the left hip injury at 4%, which resulted in a final assessment of WPI of 6%. Mr Kirkpinar's application for further assessment 1. Section 62 of the MAC Act permits a matter referred for assessment under Part 3.4 to be referred again on one or more further occasions, including "by any party to the medical dispute, but only on the grounds of the deterioration of the injury or additional relevant information about the injury": s 62(1)(a). Section 62(1A) relevantly precludes a further referral unless "the deterioration or additional information is such as to be capable of having a material effect on the outcome of the previous assessment". 2. On 15 September 2021, Mr Kirkpinar applied for a further medical assessment. In his brief supporting submissions, Mr Kirkpinar relied on the deterioration of his left hip injury since 5 May 2015 and referred to having undergone a total left hip replacement. He sought a further assessment "in relation to the level of his whole person impairment as a result of his accident injuries". 3. NRMA opposed the application for further medical assessment. In its submissions dated 17 September 2021, NRMA argued that the need for the left hip replacement surgery was not caused by the accident but by significant pre-existing pathology in the left hip and/or a subsequent intervening event on 18 July 2012, stating: "That is, the claimant would have required the surgery irrespective of the accident". NRMA relied in this respect on a report of Dr Richard Powell dated 7 January 2021, who stated that the total hip replacement "was required for the management of end-stage osteoarthritis"; and that as the underlying degenerative disease was a pre-existing condition it was "likely that he would have required this surgery irrespective of any contribution from the motor vehicle accident". NRMA also submitted that contrary to the position of Assessor Long, the pre-accident medical material was sufficient to establish a pre-existing impairment in the left hip, such that even if there was a present day impairment that was caused by the accident (which NRMA disputed), the overall whole person impairment would not be greater than 10%. 4. In its submissions, NRMA called attention to particular pre-accident medical material relating to the left hip, including the following: "(e) On 1 March 2011, there had been pain in the left hip for the previous few months. (f) X-rays of both hips performed on 2 March 2011 revealed degenerative changes which were most severe on the left. There was also marked joint space narrowing, osteophytes and subchondral cysts. (g) The claimant saw A/Prof Aggarwal, neurologist, on 11 February 2011 and 29 March 2011. He reported ongoing left-sided weakness generally as well as, inter alia, pain in the lower back and left hip. On examination, range of movement of the hip was significantly restricted and there was weakness of the lower left limb. (h) There was further mention of hip pain to the GP on 11 March 2011, 28 March 2011 and 8 April 2011. On the latter occasion, a recent bone scan confirmed the presence of significant degenerative changes in the hip. (i) MRI of the left hip on 30 June 2011, performed less than three weeks before the accident, revealed prominent elongation of the acetabular rim, degenerative tears of the labrum, peripheral articular wear and joint effusions. (j) The claimant underwent a further scan of the left hip on the date of accident at Royal Prince Alfred Hospital which demonstrated osteoarthritic changes with marked joint space narrowing, prominent of the femoral head/neck junction in keeping with femro-acetabular impingement as demonstrated by the previous scan. (k) No new pathology in the left hip has been identified by any post-accident scans. (l) On 18 July 2012, the claimant rolled onto his left hip in bed and heard a popping sound which was followed by a sharp and stabbing pain. The pain was so severe he attended Royal Prince Alfred Hospital the following day and, although a cortisone injection was administered, there was no relief. (m) Thereafter, the claimant reported to his doctors significantly greater pain and restriction involving the left hip than prior to that date. Notwithstanding, the predominant view was that the primary cause of those problems was the significant pre-existing degenerative pathology." 1. On 14 November 2022, NRMA applied to rely on supplementary submissions, medical records, and medical reports. In its supplementary submissions, NRMA noted that a delegate of the President had referred all injuries for further assessment (not just the left hip) and thus addressed Mr Kirkpinar's claims relating to the right hip, the cervical spine and the lumbar spine. In relation to the latter, NRMA referred to pre-accident medical material which indicated that Mr Kirkpinar complained of experiencing pain in his lower back in connection with the stroke that he suffered in 2008, including in the months before the motor accident in 2011; and it noted that there were only sporadic references to lower back pain in the medical material that post-dated the motor accident. NRMA submitted that the medical assessor "would find the claimant suffered from pre-existing problems with his lumbar spine and the accident caused, at most, a temporary aggravation of same and/or soft tissue injury which subsequently resolved". 2. NRMA also made further submissions about the left hip to address additional pre-accident medical material that it had received since it filed its original response. That material included a letter from Dr Ibrahim, sports physician, to Mr Kirkpinar's physiotherapist, David Pugh, dated 14 June 2011. Dr Ibrahim referred to having seen Mr Kirkpinar that day. He noted that an MRI scan Mr Pugh had organised "demonstrated moderate osteoarthritis in both hips with an effusion in the left side". Under the heading "Impression" Dr Ibrahim stated: "Musa has moderate hip osteoarthritis. It is likely he will need a total hip replacement. In the meantime, Musa was given an ultrasound guided injection of cortisone with 20mg of Kenacort and 5mls of local anaesthetic using a sterile technique. He tolerated this procedure well and within a few minutes, most of his symptoms had disappeared. It is likely Musa will need these injections over the next two to three years until he is strong enough to undertake an inevitable hip replacement. …" (Emphasis added.) 1. On 22 November 2022, Mr Kirkpinar was examined by Assessor Home. In his reasons, Assessor Home noted that Mr Kirkpinar reported "constant low back pain radiating across the lower back evenly", and that the pain increased with sitting for more than ten minutes. He had a maximum sitting tolerance of no more than 40 minutes, which was similar for driving, and he walked with a stick for balance as he was concerned about falls. In relation to his left hip, Mr Kirkpinar reported that the intrinsic sharp pain in the hip had resolved following the hip replacement, but there was continuing pain, which increased with walking, that he attributed to a local tendon or muscle. Mr Kirkpinar also reported further worsening pain in his right hip, particularly over the last 14 months. 2. Assessor Home undertook a detailed review of the medical reports and the radiological and medical imaging. He found that there was "good evidence of a pre-existing symptomatic left hip osteoarthritis complaint which, if assessed at that time, would have attracted a moderate impairment rating of 4% WPI in accordance with the methodology set out in Table 40, AMA4, page 78 taking into account the documented clinical findings…". Assessor Home noted that in so far as Assessor Long had opined that no record of limitation of movement of the left hip had been recorded, this was not consistent with his review of the medical records. Under the heading "Diagnosis and causation", Assessor Home recorded that he was satisfied "that there was an aggravation of symptoms from the motor vehicle accident vs bicycle". He then extracted cl 6.6 and cl 6.7 of what he described as the "SIRA Guidelines". Although what he set out was in similar terms to cl 1.6 and 1.7 of the Guidelines, which I have extracted above, the numbering suggests that he was referring to the guidelines made under the Motor Accident Injuries Act. No party suggested that anything turned on the difference. 3. Assessor Home concluded: "In this case I am satisfied that the alleged factor has caused a contribution to the worsening of the impairment of the underlying arthritis. I am satisfied, having viewed all of the medical evidence that the alleged factor did cause and contribute to [the] worsening of the impairment. In this regard I place weight on the reports of Associate Professor Aggarwal, who had examined the claimant prior to and after the subject accident. Whilst the report of Dr Powell is persuasive, the totality of [the] evidence, including the reports of Associate Professor Aggarwal and Dr Anderson support a material aggravation of the hip complaint and underlying arthritis by the subject accident. I find that the motor vehicle accident was a contributing cause which was more than negligible as required under Section 6.7. I find that the motor accident contributes to the progression of symptoms for which the total hip replacement was undertaken in 2016. There was aggravation of the underlying degenerative change. This assessment is made and takes into account the fact that the claimant was already advised that he would likely require a total hip replacement by his treating doctors prior to the subject motor vehicle accident. I am satisfied the claimant sustained [a] soft tissue injury to the cervical spine and to the lumbar spine. It appears that there has been some progression of his complaints in the lumbar spine since the previous assessment of Assessor Long. In relation to the right hip, there was pre-existing degenerative change at the right hip, as documented in the pre-accident medical record. He (sic) symptoms were aggravated by the subject accident." 1. Assessor Home assessed the WPI rating for the lumbar spine as 5%, and noted that because Assessor Long indicated a WPI of 0% for this injury he could not determine that there was a rateable permanent impairment before the deterioration in his lower back condition in recent years. He assessed the cervical spine and the right hip as having 0% WPI attributable to the motor accident. For the left hip, Assessor Home assessed the WPI as 20%, but deducted 4% for the pre-existing symptomatic osteoarthritis, resulting in 16% WPI for the left hip and a total WPI of 20% (on the basis of the combined values chart at page 322 in AMA4). NRMA's application for review of Assessor Home's medical assessment 1. Section 63(1) of the MAC Act permits a party to a medical dispute to apply to the President to refer a medical assessment by a single medical assessor to a review panel for review, limited to the ground that the medical assessment "was incorrect in a material respect". The President may arrange for referral only if satisfied "that there is reasonable cause to suspect that the medical assessment was incorrect in a material respect having regard to the particulars set out in the application": s 63(2B). However, once a referral is made, the review of a medical assessment is not limited to a review only of that aspect of the assessment "and is to be by way of a new assessment of all the matters with which the medical assessment is concerned": s 63(3A). Section 63(4) provides that a review panel may confirm the medical assessor's certificate, or revoke that certificate and issue a new certificate "as to the matters concerned". Section 61 of the MAC Act applies to any new certificate: s 63(6). 2. On 9 May 2023, NRMA applied for review of Assessor Home's medical assessment. In relation to the left hip, the focus of NRMA's submissions on the review was Assessor Home's approach to causation, submitting that he had erred in the following respects: "(a) Asked himself the wrong question (because the issue for determination was not whether the accident caused an aggravation of pathology in the claimant's left hip but, rather, whether he would have required total hip replacement surgery irrespective of the accident). (b) Failed to address and consider the insurer's submission that the claimant would have required left hip surgery irrespective of the accident. (c) Failed to apply the correct test of causation as highlighted in AAI t/as AAMI v Phillips [2018] NSWSC 1710 at [26]-[42], namely: (i) Whether the subject accident made at least a material contribution to the need for the surgical procedure, and (ii) Whether the need for the surgical procedure conducted in 2016 would not have arisen but for the occurrence of the subject accident. (d) Failed to address and consider the insurer's submissions that the symptoms in the claimant's left hip deteriorated significantly when he rolled onto the left hip in bed on 18 July 2012 and heard a popping sound which was followed by a sharp and stabbing pain." 1. In relation to the first of these alleged errors, NRMA submitted that the total hip replacement surgery gave rise to the relevant impairment, referring to Table 64 and Table 65 of AMA4. NRMA submitted that, on the correct approach to causation: "9. … Assessor Home was required to determine not whether there was an aggravation of pathology in the claimant's left hip caused by the accident, but, rather whether he would have required total hip replacement surgery had the accident not occurred. … 10. Accordingly, in the event the claimant would have required total left hip replacement surgery had the accident not occurred (a position which the insurer submits is irrefutable from the medical material before the Commission), a finding of causation could not be sustained. 11. Assessor Home did not consider that issue notwithstanding the insurer's submissions raised same.…" 1. NRMA pointed to various medical reports that were before Assessor Home on the basis of which, it submitted, he should have concluded that Mr Kirkpinar would have required total hip replacement surgery had the accident not occurred. NRMA submitted that Assessor Home should also have concluded that the improvement in Mr Kirkpinar's symptoms as reported to Dr Ibrahim in November 2011 was consistent with its submissions regarding the incident on 18 July 2012, which Assessor Home did not consider. Relevantly, Dr Ibrahim had stated: "Musa presented today with some mild pain in his left hip. As you know, in June he was given an injection of cortisone which has helped him since then. Unfortunately, recently he has been hit by a car whilst on his bike, which has set him back a little bit. He still feels better than before the initial cortisone injection done in June." 1. In relation to the lumbar spine, NRMA submitted that Assessor Home did not consider its argument that Mr Kirkpinar had a pre-existing problem, and that the accident caused an at most temporary aggravation. Instead, Assessor Home did little more than diagnose the problem. Contrary to Assessor Home's assertion that the notes of Mr Kirkpinar's visits to Royal Prince Alfred Hospital in February 2011 and March 2011 did not disclose any complaint of back pain, NRMA pointed to a number references to lower back pain in the notes of Associate Professor Aggarwal, neurologist. It also relied on A/Prof Aggarwal opining, in the letter to Dr Iyer, Mr Kirkpinar's general practitioner, dated 29 March 2011, that "there was likely 'lumbar facet joint dysfunction, resulting in irritation of the left L5 nerve root, as [the claimant] he had pain on extension rather than flexion with radiation of pain posteriorly down his left [leg]'". NRMA submitted that Assessor Home provided no reasoning as to the basis on which he accepted that the lumbar spine impairment was related to the motor accident, in circumstances where it had placed causation of any impairment in issue. It also submitted that Assessor Home needed to set out the basis on which he had accepted that the progression in this injury since the previous assessment was causally related to the motor accident. 2. I pause at this point to note that NRMA's summary of A/Prof Aggarwal's opinion in its submission to the review panel overstated what he wrote in the letter of 29 March 2011. What A/Prof Aggarwal there said was: "It is possible that Mr Kirkpinar's recurrent pain is due to lumbar facet joint dysfunction, which is resulting in irritation of the left L5 nerve root, as [the claimant] he had pain on extension rather than flexion with radiation of pain posteriorly down his left leg suggesting. To investigate his symptoms further, I have organised a Bone scan with SPECT imaging of his lumbar spine as this will show abnormalities in the lumbar spine, but also hips, better than a MRI scan of the hip, as suggested. If there are areas of inflammation, I would be happy for YOU could organise cortisone injections to the area of maximum inflammation." (Italics emphasis added, bold emphasis in original). 1. A letter to Dr Iyer from Dr John Yang of the Pain Management Centre at Royal Prince Alfred Hospital, which was in the material before the review panel and to which Mr Kirkpinar called attention in these proceedings, was not dated but referred to A/Prof Aggarwal's recommendations and to the motor vehicle accident in July 2011. In relation to the imaging that A/Prof Aggarwal recommended, Dr Yang noted that "[t]otal body scan + SPECT revealed degenerative disease in the left hip only with no evidence of facet joint arthritis". 2. On 28 May 2023, Mr Kirkpinar lodged a reply to the application for review contending that the assessor did not err in his approach to causation. Mr Kirkpinar submitted that Assessor Home had appropriately considered NRMA's submissions regarding causation both in relation to his left hip and the lumbar spine. 3. On 14 June 2023, a delegate of the President determined that she was satisfied that there was reasonable cause to suspect that the medical assessment was incorrect in a material respect and accepted the review application pursuant to s 63(2B) of the MAC Act. On 9 October 2023, the review panel directed Mr Kirkpinar to attend upon the two members of the review panel who were medical assessors for examination on 30 October 2023. According to the review panel's reasons, Mr Kirkpinar attended an examination with Assessor Couch on that date, for approximately 70 minutes, accompanied by his older brother: at [10]-[11]. That the examination was conducted by one member of the review panel likely explains why parts of the review panel's reasons addressing the examination and the results thereof are written in the first person singular voice. The determination of the review panel 1. On 26 April 2024, the review panel issued its certificate and reasons. The certificate stated: "WHETHER THE DEGREE OF PERMANENT IMPAIRMENT OF THE INJURED PERSON AS A RESULT OF THE INJURY CAUSED BY THE MOTOR ACCIDENT IS GREATER THAN 10% 1. The Panel revokes the Certificate of Medical Assessor Home dated 12 April 2023. The claimant has suffered a physical injury being an injury to his lumbar spine giving rise to an impairment of 5%. The claimant suffered a total hip replacement of his left hip giving rise to a current whole person impairment of 20%. A deduction of 10% WPI is made because of documented pre-existing symptomatic permanent impairment, leaving a net impairment of 10% caused by the accident. The claimant suffered a soft tissue injury to the cervical spine giving rise to a whole person impairment of 0%. The claimant's whole person impairment of 15% is greater than 10% whole person impairment." 1. Early in its reasons, the review panel noted that when it conferred on 6 September 2023, it considered "that the primary issue of contention between the parties is whether or not the motor vehicle accident caused or hastened the need for the left hip replacement which the claimant has undergone": at [10]. The review panel noted that its assessment of this issue was complicated by "an unrelated disability consequent to a stroke which left the claimant with hemiplegia": at [10]. In addition to the results of the examination, the review panel stated that it had considered the material contained in the application and reply that was before Assessor Home, as well as material accepted by the President's delegate, making specific reference to the parties' submissions and the clinical records and notes provided by Mr Pugh, Dr Iyer, Dr Ibrahim, Dr Todorovic (Mr Kirkpinar's subsequent GP) and Mr Maher (a chiropractor): at [12]. 2. The review panel set out a summary of the pre-accident medical records, referring to Mr Kirkpinar's stroke in December 2008 and to his complaints about left hip pain in 2011 before the accident: at [13]-[23]. The review panel made specific reference to Mr Kirkpinar's complaints of left hip pain in the records of A/Prof Aggarwal and Dr Iyer in March 2011, and the bilateral hip degenerative changes shown in imaging from that time. It also referred to A/Prof Aggarwal's noting that there was no complaint of back pain and his request for further imaging to exclude lumbar spine pathology: at [19]. 3. The review panel also referred to the records of Mr Pugh from June 2011, which noted worsening left hip pain from February 2011 and that an MRI scan showed "widespread deterioration", and added that Mr Kirkpinar "had been advised that he was not an ideal candidate for total hip replacement at this stage as his motor control still has the capacity to improve". The review panel also referred to Dr Ibrahim's letter to Mr Pugh of 14 June 2011, which I have extracted at [28] above. 4. The review panel also summarised the post-accident medical records, commencing with the ambulance report and hospital admission summary from the date of the accident, both of which recorded that Mr Kirkpinar complained of pain in the lower back: at [24]-[25]. The review panel referred to the report of a neurologist, Professor Anderson, dated 25 October 2011, in which Professor Anderson noted that Mr Kirkpinar had had some setbacks in recovery and referred to the motor accident "further injuring his hip and knee on the left side": at [27]. The review panel also referred to the report of Dr Ibrahim dated 2 November 2011 and set out the effect of the extract that I have set out above: at [28]. 5. The review panel summarised Dr Iyer's records between July and October 2011, in which he documented complaints of pain that Mr Kirkpinar reported including in the lower back and in the left hip: at [30]-[31]. It noted that in a record of 26 October 2011, Dr Iyer recorded a lot of pain in the left groin and lower back, that he did not have left groin and left lower back pain before the motor accident, and that the pain was exacerbated by walking for 10 minutes: at [31]. The review panel also referred to a report from August 2012 of Dr Purcell at the Pain Management Centre, who documented ongoing left hip pain for which Mr Kirkpinar required a crutch to mobilise, and that with the progression of degenerative changes in the left hip they discussed a hip replacement: at [32]. 6. The review panel noted that there was subsequent correspondence from treating practitioners about the gradual worsening of left hip symptoms leading to the total left hip replacement in September 2016: at [34]. It stated that it had "carefully considered the various medicolegal reports" which Assessor Home had reviewed, although the reports did "not significantly affect the Panel's conclusions": at [35]. The review panel also referred to Assessor Long's certificate of 5 May 2015 and his acceptance "(much closer to the date of the accident, and when Mr Kirkpinar's memory was apparently satisfactory)" of causation of an aggravation of pre-existing osteoarthritis of the left hip: at [36]. 7. The review panel then summarised the examination that Mr Kirkpinar attended, noting that after his arrival "it became obvious that his memory was much worse than when he had attended Medical Assessor Home in November 2022": at [40]. Reference was made in this context to Mr Kirkpinar suffering a further stroke in late 2022 that was not apparently mentioned in the documents available to the panel: at [37]. Mr Kirkpinar was unable to remember the full chronology of his hip symptoms or any symptoms before the motor accident: at [40]. He did appear to remember the motor accident, and he "did recall being a lot worse with his mobility after being knocked off his bike", but he could not give more specific details: at [43]. When asked what areas of his body he thought had been affected by the accident, Mr Kirkpinar referred to his "whole left side", including his left hip: at [44]. 8. The review panel then detailed Mr Kirkpinar's report of his symptoms, his present activities and current treatment, and the physical examination: at [44]-[59]. In relation to the lumbar spine, the review panel noted that Mr Kirkpinar had a forward stoop at the waist while standing or walking, and he did not report any tenderness on palpation. On measuring his active range of motion, it was noted that his "flexion was almost full and [he was] able to reach [his] fingertips to his knees, but he could not extend beyond the neutral position, complaining of low back pain when he tried": at [53]. Active range of motion of the hips was also measured and the results reported: at [57]. Specifically in relation to the hip replacement, the review panel stated: "59. Rating the left THR [total hip replacement] from Table 65 of AMA4, based on my examination, I assessed 59 points from Table 65. There was no loss of points from Section D (deformity) based on my examination. Note that when assigning the points rating, I did make allowance for his left-sided stroke. From Section E (range of motion), there were 3 added points. This gives a total of 62 points which is very close to the assessment of rating of Assessor Home in November 2022 of 60 points. This places him firmly in the 'fair' range, giving 20% WPI." 1. Under the heading "Panel conclusions", the review panel referred to the difficulties caused by Mr Kirkpinar's recent stroke and the passage of time, with 12 years between the motor accident and the review panel's consideration of the matter: at [60]-[61]. The review panel then stated: "62. Having carefully considered all the information available, the Panel considers that, on the balance of probabilities, the accident on 16 July 2011, in which Mr Kirkpinar was knocked off his pushbike by a car, was a contributing cause, which was more than negligible, to aggravation of pre-existing osteoarthritis in his left hip. The Panel considers that this resulted in his needing THR earlier than would otherwise have been the case." 1. After referring to Assessor Home's approach to the pre-existing symptomatic impairment of the left hip, the review panel considered that issue and formed the view "[a]fter extensive deliberation" that Assessor Home's deduction of 4% WPI was "probably an inadequate deduction": at [64]. Reference was made to the observation of the two medical members of the review panel, applying Table 62 in AMA4, "Arthritis Impairments Based on Roentgenographically Determine Intervals", that based on an MRI dated 1 July 2011 the most likely cartilage interval would have been 1mm, giving 10% WPI, and that the MRI findings did not suggest a zero cartilage interval (which would give 20% WPI): at [65]. Applying the approach in cl 1.31 of the Guidelines (see [18] above), the review panel concluded that the "net impairment resulting from the subject accident and hastening of THR is 10%": at [65]. 2. In relation to the other injuries, the review panel stated: "66. Findings in the lumbosacral spine are very similar to those of Medical Assess or Home, with quite marked dysmetria, assessed as DRE Lumbosacral Category II. The Panel assessed the claimant's lumbosacral to be DRE Category II and giving rise to a WPI of 5%. 67. There was some restriction of AROM [active range of motion] in the right hip, probably due to osteoarthritis-there was evidence of this on the bone scan. The Panel did not consider that there was sufficient evidence to attribute this to the accident. 68. There was dysmetria in the cervical spine, with loss of extension and rotation to the left (Medical Assessor Home had found no dysmetria). Although Medical Assessor Home obtained a history of constant right-sided neck pain in November 2022, on this occasion Mr Kirkpinar denied pain, and his brother said that he had not heard him complain of neck symptoms. Interpretation of this history is made more difficult by the recent deterioration in his memory. 69. If the Panel were to accept causation of a cervical spine injury (as did Medical Assessor Home), the injury would now be assessed as DRE category II, giving 5% WPI. However, given the absence of current reported symptoms, the Panel takes a conservative approach, and has not included this in the total impairment." 1. The review panel concluded that as its "examination findings, determination of causation and determination WPI were different to the findings of Medical Assessor Home for the reasons mentioned above", it was of the view that a new certificate should be issued "in accordance with the Panel's finding a WPI of 15% consequent on the claimant's hip and lumbar spine injuries": at [70]. In its final paragraph, headed "Determination", the review panel revoked Assessor Home's certificate and determined that "[t]he claimant has suffered physical injury being a soft tissue injury to his left hip and lumbar spine giving rise to a 15% WPI": at [71]. Ground 1: the review panel's approach to causation Mr Kirkpinar's left hip injury 1. NRMA submitted that the review panel failed to carry out its statutory task according to law because it failed to consider "whether, with respect to impairment caused by the surgery, factual causation per section 5D(1)(a) of the [Civil Liability Act] was established (ie, was the accident a necessary condition of the impairment in the left hip, which was caused by the surgery)" . When asked in the hearing to explain why the surgery was the injury causing the impairment, counsel submitted that it was because "prior to the surgery, the whole person impairment had been assessed by Assessor Long as not exceeding the threshold", and that performance of the hip replacement surgery "in and of itself is what causes the impairment to be over 10%". 2. There was force in the responsive submission of senior counsel for Mr Kirkpinar that NRMA's characterisation of the hip replacement surgery as an injury to be separately considered was incorrect. Care must be taken not to confuse the impairment being assessed with the assessment of the degree of that impairment. The hip replacement surgery was central to Mr Kirkpinar's application for further medical assessment, but as part of his claim that there had been a deterioration in his level of impairment as a result of the injuries caused by the motor accident. That was the dispute that was referred to Assessor Home and, in turn, to the review panel. 3. Relatedly, NRMA relied on the decision in Jobling v Associated Dairies Ltd [1982] AC 794 ("Jobling"), as well as decisions of the Court of Appeal which have applied that decision, DNM Mining Pty Ltd v Barwick [2004] NSWCA 137 and K'Mart Australia Ltd v McCann [2004] NSWCA 283, for the proposition that if an underlying condition would ultimately have required a total hip replacement, it did not follow from bringing forward that surgery that the impairment was caused by the motor accident. Apart from those cases involving claims for economic loss, a difference from the present case that NRMA acknowledged, the analogy is inapt in the circumstances of this case. As senior counsel for Mr Kirkpinar submitted orally, the analysis in Jobling and the other authorities upon which NRMA relied concern how to accommodate the occurrence of an unconnected supervening injury. Characterising the total hip replacement surgery in this way served only to distract from an assessment of whether the review panel performed its statutory task of determining the medical assessment matter referred to it. 4. NRMA submitted in this respect that the review panel failed to discharge its obligation under the Guidelines to consider common law principles of causation, because the review panel did not consider whether the surgery would have arisen but for the occurrence of the motor accident. In respect of this argument, counsel for NRMA described the impairment for assessment as "the current state [of Mr Kirkpinar's left hip injury] post-surgery and not the timing of the surgery". Counsel submitted that the review panel's error was "that it considered whether the timing of the surgery had been brought forward rather than considering whether the motor accident was a necessary condition of that surgery occurring by the time of the medical assessment". 5. In Rodger v De Gelder [2015] NSWCA 211; 71 MVR 514 ("Roger v De Gelder") at [17], Gleeson JA described it as "well established" that "the degree of permanent impairment as a result of the injury caused by the motor accident (s 58(1)(d); s 131) is unequivocally for the medical assessor, or review panel, as the case may be, including the element of causation". As his Honour further stated at [90], it is "mandatory that the review panel address the medical assessment matter and carry out the statutory function". In considering causation in the context of an assessment of permanent impairment for the purposes of s 58(1)(d) of the MAC Act, cl 1.7 of the Guidelines describes the causation inquiry as involving a determination as to "whether the injury (and the associated impairment) was caused or materially contributed to by the motor accident": cl 1.7. In the context of s 5D of the Civil Liability Act, Kirk JA recently elucidated the relevant inquiry in Value Constructions Pty Ltd v Badra [2024] NSWCA 181 at [6] (Leeming JA and Griffiths AJA agreeing): "… The issue under s 5D of the Civil Liability Act 2002 (NSW) (CLA) is relevantly whether the negligence was a necessary condition of the occurrence of the harm. That notion has been taken to include where the tortfeasor's negligence materially contributed to the harm even if there were other conjunctive causes, just as under the previous common law: Amaca Pty Ltd v Booth [2011] HCA 53; (2011) 246 CLR 36 at [70]; Strong v Woolworths Ltd [2012] HCA 5; (2012) 246 CLR 182 at [20]-[30]. It is necessary only that the relevant act or omission play some part in contributing to the loss, even if minor: Hunt & Hunt Lawyers v Mitchell Morgan Nominees Pty Ltd [2013] HCA 10; (2013) 247 CLR 613 at [45]; Gould v Vaggelas [1984] HCA 68; (1984) 157 CLR 215 at 236. …" 1. As Mr Kirkpinar submitted, what Kirk JA said in Badra finds reflection in cl 1.7 of the Guidelines, which states that "[t]he motor accident does not have to a sole cause as long as it is a contributing cause, which is more than negligible". Importantly for present purposes, cl 1.7 also states that considering the question "Would this injury (or impairment) have occurred if not for the accident?" is not a definitive test and, indeed, "may be inapplicable where there are multiple contributing causes" (emphasis added). 2. In the review panel's reasons at [62] it accepted that at the time of the motor accident, Mr Kirkpinar had pre-existing osteoarthritis in the left hip. However, it also found that the motor accident in July 2011 aggravated that pre-existing condition, contributing to the need for a hip replacement in 2016. There were thus, on its findings, multiple contributing causes for Mr Kirkpinar's current left hip impairment at the time of its assessment, of which the motor accident was one, and its contribution more than negligible. 3. The review panel went on to find, in the second sentence of [62], that "this" (being the pre-existing osteoarthritis as aggravated by the motor accident, as referred to in the previous sentence) resulted in Mr Kirkpinar needing the total hip replacement when he did. True it is that the review panel stated that this was "earlier than would otherwise have been the case", but in making that statement it was responding to the very issue that NRMA had raised. It was not thereby making a finding that Mr Kirkpinar would otherwise have required hip replacement surgery by a particular point time; nor did it need to in order to determine the medical dispute to which s 58(1)(d) refers. 4. NRMA's submission to the contrary entailed putting the fact of the motor accident to one side and asking, in that hypothetical (indeed, unreal) scenario, whether the surgery would have been required at any point before the review panel's assessment. In circumstances where the review panel found that the motor accident aggravated Mr Kirkpinar's left hip injury and that the aggravation contributed to the hip replacement occurring when it did, no purpose would be served by going on to ask whether the hip replacement would have occurred anyway. What the review panel said about the timing of the hip replacement surgery did not demonstrate that it asked itself the wrong question, or failed to ask itself a question that it was required to ask. 5. NRMA submitted that the review panel's focus on timing could be productive of absurdity. It submitted by way of example that if a motor accident brought forward a surgery by one day, that might be found to satisfy the requisite causal connection such that the insurer would be liable if the injured person's degree of permanent impairment exceeded 10%. That posited absurdity rested on a misunderstanding of what the review panel found. Further, as senior counsel for Mr Kirkpinar submitted at the hearing, that the WPI would exceed 10% in that circumstance would not inexorably follow. As I have pointed out above, the Guidelines contain provisions by which allowances are made for the calculation of pre-existing impairments (cl 1.31 and cl 1.32) and for subsequent injuries (cl 1.34). In the present case, the review panel applied cl 1.31 and cl 1.32 of the Guidelines so as to account for Mr Kirkpinar's pre-existing left hip pathology before the motor accident. Contrary to the position of Assessor Long in 2015, who found no pre-existing impairment, and of Assessor Home, who assessed the pre-existing impairment at 5%, the review panel assessed Mr Kirkpinar's pre-existing impairment at 10%, resulting in 10% WPI for the left hip (which, of itself, would not have satisfied the "greater than 10% threshold" in s 131 of the MAC Act). 6. NRMA submitted that the decision of Davies J in AAI Ltd t/as AAMI v Phillips [2018] NSWSC 1710; 87 MVR 20 ("Phillips") supported the need to make an inquiry of the nature that it submitted should be made. However, the particular paragraphs that NRMA relied upon need to be read in the context of the circumstances of that case. Phillips involved a dispute under s 58(1)(b) of the MAC Act as to whether particular treatment provided or to be provided to the injured person "relates to the injury caused by the motor accident". As Davies J set out at [1] of his reasons for judgment, the first defendant in that case was involved in three motor vehicle accidents, respectively occurring on 4 June 2010, 16 July 2012 and 24 October 2012. The first defendant alleged that he suffered injuries to his cervical, thoracic and lumbar spines and both shoulders, which were caused by each accident. In June 2016, the first defendant was referred to a neurosurgeon who recommended that he undergo an anterior surgical decompression and fusion at the C5/C6 level: at [3]. 7. An assessor determined that the proposed surgery was causally related to the second and third motor accidents, but not the first: at [4]. In upholding the medical assessor's certificate, a review panel found that the second and third motor accidents caused soft tissue injuries that increased the first defendant's neck symptoms immediately afterwards. On the basis of this increase in symptoms, the panel considered that the proposed surgery was related to those two accidents, even though it also emphasised that the neck injury from both accidents was minor and had not resulted in any structural or neurological injury warranting the proposed neck surgery. The plaintiffs, who were the respective insurers in relation to the second and third motor accidents, submitted before Davies J that for either of those accidents to have been causative of the need for the proposed surgery, the accident had to have made at least a material contribution to the need for the surgery. The plaintiffs also submitted that the review panel had to consider whether the need for the proposed surgery would not have arisen but for the occurrence of one or more of the accidents. Instead, the review panel applied a test of whether each of the second and third accidents had resulted in an increase in the first defendant's neck symptoms. 8. NRMA relied on the following paragraphs of Davies J's reasons: "[28] The requirement in s 58(1)(b) is to determine whether the treatment relates to the injury caused by the accident. If the injury that existed at the time of the Panel's assessment was not the injury caused by the accident (the mild soft tissue injuries superimposed on the chronic degenerative changes) but, rather, simply the continuation of those pre-existing degenerative changes, then the treatment cannot relate to 'the injury caused by the motor accident'. [29] I accept the plaintiffs' submission that for any of the three motor accidents to have been causative of the need for the suggested surgery, the accident would have to have made at least a material contribution to the need for surgery. Further, the Panel should have considered whether the proposed surgery would not have arisen but for the occurrence of one or more of the accidents being considered." 1. NRMA submitted that the review panel in the present case was required to consider both of the inquiries to which Davies J referred in [29] of Phillips, and that it considered the inquiry in the first sentence but not the inquiry in the second. However, as I have indicated, it was necessary for the review panel to direct its attention to the surgery in Phillips because it concerned a dispute with respect to the medical assessment matter in s 58(1)(b), which requires a causal connection between the treatment in issue and the motor accident. That Davies J's comments were squarely directed at that issue is evident from the immediately following paragraphs, where his Honour stated: "[30] Where the Panel strongly suspected that the second and third accidents more likely than not did not result in any substantive change of neck condition and certainly not one which could warrant cervical fusion and decompression, and where the Panel thought it highly likely that the claimant would have severe neck pain even if the second and third accidents had not occurred, it is difficult to see how the proper test of causation has been applied by the Panel. [31] Further, the Panel found only that there were increased neck symptoms immediately after each of the second and third accidents. It is difficult to see how, in the absence of a finding that those symptoms persisted, that the proper test of causation could be applied to conclude that those accidents were causally related to the need for surgery." 1. By contrast with the inquiry at issue in Phillips, the focus of the inquiry in the present case was the connection between the motor accident and the injuries on the basis of which Mr Kirkpinar was claiming a present impairment. Having considered the pre-accident medical material and the post-accident medical material, the review panel concluded in the first sentence of [62] that the motor accident was "a contributing cause, which was more than negligible" to aggravation of the pre-existing osteoarthritis in his left hip. The language in this sentence reflects the language used in cl 1.7 of the Guidelines, strongly suggesting that the review panel had the Guidelines in mind in reaching its conclusion on causation: cf Jarvis v Allianz Australia Insurance Ltd [2022] NSWCA 232; 102 MVR 476 at [72] (Basten JA, Bell CJ agreeing). It follows that I reject this aspect of ground 1. Mr Kirkpinar's lumbar spine injury 1. Whereas this ground alleged in relation to Mr Kirkpinar's left hip impairment that the review panel asked itself the wrong question, the particular of NRMA's complaint regarding the lumbar spine was that the review panel failed to consider and/or determine causation at all. NRMA relied primarily on the fact that the review panel's reasons in [66] did not include a finding that Mr Kirkpinar's lumbar spine impairment was related to an injury caused by the motor accident. Mr Kirkpinar accepted that there was no finding of causation in [66], but nonetheless submitted that it could not be inferred from the review panel's reasons that it had failed to consider this issue. The question is whether NRMA's allegation that the review panel failed to consider and/or determine causation arises as a matter of inference from the absence of an express finding. 2. As the Guidelines acknowledge in cl 1.5, all assessments of the medical assessment matters in s 58(1)(d) of the MAC Act involve a determination as to whether the injured person's impairment is related to the accident in question. It is apparent from the review panel's reasons in relation to the left hip, right hip and cervical spine that the review panel was aware of the need to make that determination in relation to each impairment, with its reasons on each of those injuries referring to causation. 3. On one view, the fact that the review panel referred to causation for the other injuries tells against an inference that the review panel failed to consider causation of this injury. On the other hand, the fact that the review panel referred to causation for the other injuries highlights the contrast with its conclusions on the lumbar spine in [66]. The review panel there said nothing about causation and recorded no determination of that issue. Rather, its reasoning is addressed only to the clinical findings flowing from the examination of Mr Kirkpinar, with the review panel referring to his marked dysmetria and the assessment category as "DRE Lumbosacral Category II" being "very similar to those of Medical Assessor Home". Although senior counsel for Mr Kirkpinar submitted that the reference to Assessor Home's reasons amounted to an adoption of all of the findings he made, the clinical focus of [66] does not support that conclusion. 4. It was necessary for the review panel to make a determination of causation in relation to this injury, not least because in its application for review NRMA expressly raised the issue. In the absence of a finding on causation regarding the lumbar spine and given the clinical focus of what the review panel did find in [66], I consider that the review panel failed to determine the question of causation for this particular impairment. As Hamill J stated in Sadsad v NRMA Insurance Ltd [2014] NSWSC 1216; 67 MVR 601 at [47], gaps in the reasons may be filled by necessary inference but they cannot be filled by an assumption that a decision was made according to law. The general terms in which the review panel expressed its conclusion in the reasons at [71], in terms of Mr Kirkpinar having "suffered physical injury being a soft tissue injury to his left hip and lumbar spine giving rise to a 15% WPI", does not call for a contrary conclusion, noting that causation regarding the left hip injury is addressed in the reasons and causation regarding the lumbar spine is not. 5. It follows that there has been a failure on the part of the review panel to discharge the function conferred on it by the statute with respect to the medical assessment matter referred to it: see Rodger v De Gelder at [90]. Mr Kirkpinar submitted that on the medical material on the lumbar spine before and after the motor accident, there was only one conclusion open in relation to causation of that injury. In circumstances where there was a large amount of medical material before the review panel, which covered a significant period of time both before the motor accident in 2011 and afterwards up to the time of the review panel's assessment, reaching a conclusion to that effect in circumstances where the review panel made no findings would involve placing myself in the position of the review panel and assuming its functions. In LPDT v Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs (2024) 98 ALJR 610; [2024] HCA 12 at [15], the High Court reiterated the need for caution in engaging in a process of that kind. Applying the threshold for materiality as discussed in that decision at [14], there was a realistic (in the sense of not far-fetched or fanciful) possibility that the decision that was made in fact could have been different if the error had not occurred and the review panel had discharged its function according to law. It follows that NRMA has established jurisdictional error on the part of the review panel. Ground 1 should be upheld. Ground 2: adequacy of reasons 1. NRMA next contended that the review panel failed to provide adequate reasons for its decision, giving rise to an error of law on the face of the record. The summons identified the following particulars: "The review panel failed to expose its actual path of reasoning for its findings including the following: (a) Whether and why the hip injury sustained in the accident was a necessary condition of the surgery and consequent impairment. (b) Why the hip injury sustained in the accident was a contributing cause, more than negligible, of the surgery and the consequent impairment. (c) Whether and why it was appropriate for the scope of the insurer's liability to extend to the impairment caused by the hip replacement surgery. (d) Why and/or how any increased pain in the left hip following the accident caused advancement of the degenerative changes in the left hip that were the reason for the surgery. (e) Why the timing of the surgery was brought forward by the injury caused by the motor accident. (f) To what degree the timing of the surgery was brought forward by the injury caused by the motor accident. (g) Whether and why the impairment in the lumbar spine is causally related to the accident." 1. The applicable principles were not in dispute, with both parties referring to the decision of the High Court in Wingfoot Australia Partners Pty Ltd v Kocak (2013) 252 CLR 480; [2013] HCA 43 ("Wingfoot"). In Wingfoot at [43], the High Court observed that the content of a statutory duty to give reasons "defines the statutory standard that a written statement must meet to fulfil it". At issue in Wingfoot was the standard required of a Medical Panel under the Accident Compensation Act 1985 (Vic), which has been described as an analogous statutory regime to Part 3.4 of the MAC Act: Frost v Kourouche (2014) 86 NSWLR 214; [2014] NSWCA 39 at [2], [40]. Section 68(2) of the Accident Compensation Act required the Medical Panel to whom a medical question was referred to give a certificate as to its opinion on the medical question and a written statement of reasons for its opinion. In relation to that requirement, the High Court stated at [55]: "… The statement of reasons must explain the actual path of reasoning by which the Medical Panel in fact arrived at the opinion the Medical Panel in fact formed on the medical question referred to it. The statement of reasons must explain that actual path of reasoning in sufficient detail to enable a court to see whether the opinion does or does not involve any error of law. If a statement of reasons meeting that standard discloses an error of law in the way the Medical Panel formed its opinion, the legal effect of the opinion can be removed by an order in the nature of certiorari for that error of law on the face of the record of the opinion. If a statement of reasons fails to meet that standard, that failure is itself an error of law on the face of the record of the opinion, on the basis of which an order in the nature of certiorari can be made removing the legal effect of the opinion." 1. Relatedly, however, the High Court observed at [56] of Wingfoot that "[a] Medical Panel explaining in a statement of reasons the path of reasoning by which it arrived at the opinion it formed is under no obligation to explain why it did not reach an opinion it did not form, even if that different opinion is shown by material before it to have been formed by someone else". That observation reflected the High Court's earlier description of the function of the Medical Panel at [47], on which Mr Kirkpinar relied in his submissions: "The function of a Medical Panel is to form and to give its own opinion on the medical question referred for its opinion. … It goes too far, however, to conceive of the function of the Panel as being either to decide a dispute or to make up its mind by reference to competing contentions or competing medical opinions. The function of a Medical Panel is neither arbitral nor adjudicative: it is neither to choose between competing arguments, nor to opine on the correctness of other opinions on that medical question. The function is in every case to form and to give its own opinion on the medical question referred to it by applying its own medical experience and its own medical expertise." 1. Leeming JA quoted from [47] of Wingfoot in Insurance Australia Group Ltd t/as NRMA Insurance v Keen (2021) 399 ALR 765; [2021] NSWCA 287 ("Keen"), in a passage that is lengthy but warrants repetition in the context of NRMA's arguments on this ground and on ground 3 (I have included the grounds of review that his Honour was considering so as to provide context for what follows): "[37] Grounds 2(g) and (h) of the amended summons had been attached to the insurer's written submissions in reply supplied shortly in advance of the hearing. They were: '(g) The medical assessor was required to respond to substantial and clearly articulated arguments before him. i. The plaintiff had outlined substantial and clearly articulated arguments that went to causation including the nominal nature of the subject accident, the pre-existing injury to the claimant and reports in support. (h) The failure to respond to these arguments amounts to a denial of procedural fairness or, alternatively, a constructive failure to exercise jurisdiction and, thereby invalidates the medical assessor's decision.' [38] Some measure of precision is required when determining whether the primary judge erred as alleged in ground 3 in failing to determine a substantial part of the appellant's case, that substantial part being a complaint that the medical assessor was required to respond to a substantial and clearly articulated argument before him. Despite the similarity of the language used to describe the ground of appeal from the judgment and the ground of judicial review of the decision of the medical assessor, the two are quite different. Courts resolve disputes. Medical assessors assess the degree of permanent impairment. [39] A court's task is to resolve justiciable controversies, constituted by the parties' competing claims. A court should address substantial and clearly articulated submissions, not least because there is a danger that the entirety of the dispute will not be resolved if some substantial submission is not addressed. A court may not need to resolve every issue, but it should make it clear why the submissions it has resolved are dispositive of the case and ideally why it is unnecessary to determine other submissions which have been advanced by the parties unless they are patently insubstantial. [40] The function of the assessor is quite different. The assessor was obliged following the referral by SIRA to determine a quintessentially factual issue: the degree of permanent impairment suffered by Mr Keen caused by the motor accident, reduced to a percentage calculated in accordance with the Guidelines. As the High Court emphasised, speaking of the decisions of medical panels under the Accident Compensation Act 1985 (Vic) in Wingfoot Australia Partners Pty Ltd v Kocak (2013) 252 CLR 480; 303 ALR 64; [2013] HCA 43 at [47] (Wingfoot), the Medical Panel was not required to decide a dispute or make up its mind by reference to competing contentions or competing medical opinions: 'The function of a Medical Panel is neither arbitral nor adjudicative: it is neither to choose between competing arguments, nor to opine on the correctness of other opinions on that medical question. The function is in every case to form and to give its own opinion on the medical question referred to it by applying its own medical experience and its own medical expertise.' [41] Dr Meakin received more than 2,000 pages of material. His task was to make binding factual determinations, following his review of that material and following a clinical examination of Mr Keen. He did just that. It was not part of his function to assess the cogency of the 'case' advanced on behalf of the insurer." 1. NRMA submitted that in circumstances where causation was a significant "battle ground" between the parties, it was essential for the review panel to expose its reasoning process on that issue and that it had failed to do so. In relation to the review panel's reasons regarding the left hip, NRMA submitted that its conclusions in relation to causation at [62] were not accompanied by any reasoning, and a path of reasoning was necessary in circumstances where (at [55] of its written submissions): "…the evidence demonstrated that the claimant had already been told that he needed the surgery before the accident, was actively in pain and having treatment before the accident, had only a little setback following the accident, only reported a substantial increase in left hip pain after an intervening incident in 2012 when he rolled over in bed, and where the review panel has not explained whether or how the increased pain following the accident caused the advancement of degenerative changes that ultimately led to the surgery in 2016." 1. For the reasons explained in Wingfoot and in Keen, complaints as to this level of detail do not reflect the function of the review panel and the corresponding standard of reasons required by s 61(9) of the MAC Act. In support of its submission to the contrary, NRMA relied on the decision of Schmidt AJ in Allianz Australia Insurance Ltd v Salucci [2023] NSWSC 1593; 106 MVR 154 ("Salucci"), in particular the following paragraphs: "[79] Section 58(1)(d) being concerned as it is with not only the question of the degree of permanent impairment which resulted from Mr Salucci's injuries, but also whether they were caused by the accident, even in a case where the parties are not in dispute about causation, it has to be considered in the assessment, as was actually also explained in Brown. [80] In such a case, if there is no dispute between the parties about causation and the assessor or Panel agrees, consistently with the nature of the reasons which must be given, but little explanation of the reasons for the conclusions reached about causation will need be given, to meet the obligation to give adequate reasons. [81] But when there are live issues about causation pursued by the parties, they have to be considered and resolved, whether on assessment of the dispute or review. This the Panel failed to do, having misunderstood the law as it did." 1. As Mr Kirkpinar submitted, the review panel in Salucci was found to have given inadequate reasons on the basis that it misunderstood the law. Mr Salucci claimed that he suffered injuries to his spine and hip in a motor accident. A review panel constituted under the MAC Act concluded that he exceeded the statutory threshold for damages for non-economic loss. However, the review panel expressly refrained from dealing with the causation issues addressed by the parties in their submissions, taking the erroneous view that it had "no ability" to determine that the relevant injury was not caused by the motor accident: at [62], [72]-[73]. Her Honour's statements regarding the requirement to give reasons must be considered in that context. It certainly does not follow from what her Honour there said that it was necessary for the review panel to engage in the detailed reasoning for which NRMA contended in order to give adequate reasons. 2. As Leeming JA observed in Keen at [49], the adequacy of reasons depends upon the nature of the reasoning process. The review panel's reasons in relation to the left hip were not confined to [62] of the reasons. Its conclusions in relation to that injury continue through to [65] and must be read in context of the balance of the reasons, including its earlier review of the pre-accident and post-accident medical records and the findings from the clinical examination. The review panel's reasons regarding the left hip impairment, read against the background of the paragraphs that preceded it as well as the following paragraphs regarding the present-day impairment and the deduction for pre-existing pathology, were adequate. 3. The fact that the review panel did not expressly engage with the questions that NRMA posed in the particulars to this ground of review and explain why it did not agree does not call for a contrary conclusion. It was also not necessary for the review panel to go through the particular medical material on which NRMA relied and explain what it accepted and what it did not accept: Allianz Australia Insurance Ltd v Mackenzie [2014] NSWSC 67; 66 MVR 124 at [45]. It was sufficiently clear from the review panel's reasons that the review panel rejected NRMA's submissions on causation; and no more was required of it to discharge its duty. 4. NRMA's submissions regarding inadequacy of reasons about the left hip also rested to a significant extent on the correctness of its submissions on ground 1 about the correct approach to causation. Thus, counsel for NRMA submitted that it was necessary for the review panel's reasons to explain why the motor accident was a necessary condition of the surgery, and that the review panel erred by not identifying when the surgery would have occurred if not for the motor accident and that the reasons did not do so. As I have set out above, the review panel was not required to address when the surgery would have occurred if there had been no accident in circumstances where it found that the motor accident aggravated the pre-existing osteoarthritis so as to require the surgery when it happened. 5. In relation to the lumbar spine, NRMA submitted that it had referred to medical material that was before the review panel that indicated that Mr Kirkpinar had made complaints before the motor accident about lower back pain. However, the review panel did not give any reasons for finding that the motor accident contributed to that injury; and no actual path of reasons could be inferred to that conclusion. 6. In oral submissions, senior counsel for Mr Kirkpinar accepted that the review panel's reasons in relation to the lumbar spine impairment were "brief". However, he submitted that it was necessary to read the reasons as a whole and to read them fairly, calling attention in this regard to: 1. the reference, in [12] of the reasons, to the review panel's statement that it had considered all of the material before Assessor Home and the additional material that was not before him; 2. the review panel's review of the medical material which demonstrated that it had, in fact, reviewed all of that material, including material both before and after the motor accident that related to the lower back; 3. its reference, in [35] of the reasons, to having reviewed all of the medicolegal reports; and 4. its findings upon examining Mr Kirkpinar, which in senior counsel's submission demonstrated that the review panel was directing its attention to the assessment of impairment, not just the complaints of symptomatology. 1. Senior counsel referred to the cross-reference in [66] of the review panel's reasons to Assessor Home, submitting that the review panel was adopting his findings about impairment, including causation. He submitted that reading [66] in context and as part of the whole of the reasons, it was obvious that the condition in the lumbar spine was patently caused by this accident because it started immediately after it, when the ambulance attended the scene of the accident, and that it continued to the date of the review panel's assessment. 2. If the review panel had articulated a conclusion on causation in relation to the lumbar spine in the manner that senior counsel for Mr Kirkpinar did at the hearing, there could be no basis for NRMA's complaint. However, the only paragraph in the review panel's reasons on the lumbar spine is [66], and the review panel there said nothing about causation. Even if I had not concluded ground 1 as I have, the review panel's reasons on this issue were inadequate. There is no expression of any opinion in the review panel's reasons as to whether it was the motor accident that caused the lumbar spine injury and the associated impairment. The review panel's outline of the medical material before and after the accident, and its reference to having considered all of the material before it, do not fill that gap. Nor does the cross-reference in [66] to Assessor Home's findings, the focus of which, for the reasons I have set out above, was on Assessor Home's clinical findings. In the language of the High Court in Wingfoot at [55], the reasons did not disclose reasoning in sufficient detail to enable a court to see whether the review panel's opinion did or did not involve any error of law. 3. It follows that I would uphold ground 2. The inadequacy of the review panel's reasons constitutes an error of law on the face of the record: Wingfoot at [55], [66]. This provides a separate basis on which the review panel's decision should be set aside. 4. In light of my conclusions on grounds 1 and 2, I may be more brief in relation to grounds 3 and 4. Ground 3: failure respond to a substantial and clearly articulated argument 1. By ground 3, NRMA alleges that the Panel failed to respond to the substance of its "substantial and clearly articulated arguments, based on established facts", regarding the cause of the claimant's claimed lower bank impairment and the cause of the hip surgery and consequent impairment. In the hearing, counsel for NRMA accepted that there was overlap between this ground of review and ground 1. Counsel also acknowledged that it was necessary to consider what Leeming JA said in Keen in relation to a ground of this nature (I have set out the relevant part of his Honour's reasons in [78] above) and accepted that it was not necessary for the review panel to respond to "every line of the insurer's submissions". Nonetheless "the substance of the argument" needed to be addressed. Counsel articulated the relevant substance of its arguments to the review panel the subject of this ground as follows during oral submissions (this reflected the particulars in the summons, albeit in the reverse order): "…essentially one, the surgery was going to happen anyway and it was going to have happened by the time of the assessment. Two, there was a subsequent accident which would have caused the aggravation that would have hastened the surgery or caused the need for surgery. Not the motor accident. And then three, the lumbar spine impairment is not caused by the accident because it was pre-existing." 1. NRMA submitted that the review panel had a duty to respond to the arguments it had articulated. Causation of the left hip impairment and the lumbar spine impairment were central elements of the dispute, and in circumstances where the above three arguments were raised the review panel's failure to respond to them comprised a constructive failure to exercise jurisdiction and a denial of procedural fairness: Rodger v De Gelder at [108]-[109]. 2. The relevant failure is to respond to "a substantial, clearly articulated argument relying upon established facts": Dranichnikov v Minister for Immigration and Multicultural Affairs (2003) 77 ALJR 1088; [2003] HCA 26 at [24]. As Leeming JA stated in Keen, in evaluating an allegation of this nature made in respect of a medical assessor or, in this case, a review panel, under the MAC Act, it is necessary to bring to account the nature of the function being exercised. 3. Taking the first and second arguments the substance of which the review panel was alleged to have failed to address, the review panel clearly considered causation in relation to Mr Kirkpinar's left hip impairment. As I found in relation to grounds 1 and 2, and as Mr Kirkpinar responsively submitted on this ground, the review panel sufficiently exposed its path of reasoning on that issue. It was not necessary for the review panel to go further and respond to the particular way that NRMA put its causation argument. NRMA's submission to the contrary did not reflect the function of the review panel which, as Leeming JA said in Keen, is to form and (by its reasons) give its own opinion on the medical question referred to it, not to choose between competing arguments or assess the cogency of the parties' submissions. It thus does not follow from the absence of material in the reasons addressing the particular arguments that NRMA advanced that the review panel made the error that NRMA contended. 4. In relation to the third argument that NRMA submitted that it advanced that the review panel failed to respond to, I have found above that the review panel did not consider causation in relation to the lumbar spine injury and that its reasons on the issue were otherwise inadequate. It does not follow, however, that the review panel was required to consider the precise argument that NRMA advanced on this issue, for the reasons that Leeming JA identified in Keen to which I have referred above. The absence of adequate reasons alone does not establish this aspect of ground 3. Accordingly, I would dismiss ground 3. Ground 4: failure to evaluate evidence 1. By ground 4, NRMA alleged that the Panel failed "to intellectually engage" with the evidence in respect of Mr Kirkpinar's pre-accident left hip and lower back conditions, in particular in respect of the need for hip replacement surgery and the pre-existing lumbar spine pathology, amounting to a failure to comply with cll 1.17-1.18 of the Guidelines. NRMA contended that this was a jurisdictional error and also a failure to provide lawful reasons. NRMA's submissions are apt to confuse what the Guidelines require and what the reasons require. It does not follow from the omission of particular evidence from the reasons that the review panel did not consider particular evidence. As Mr Kirkpinar submitted, the review panel was only required to refer to the substance of the evidence, as opposed to every item of evidence. Accordingly, I would dismiss ground 4. Conclusion 1. The orders that NRMA sought in its summons included remittal of the matter to a differently constituted review panel. Mr Kirkpinar did not make any submissions on this order and I consider that it should be made. NRMA also sought its costs and no submissions were made that there should be a departure from the ordinary rule that costs should follow the event. 2. I make the following orders: 1. Amend the name of the second defendant by deleting the words "S7.26 of the Motor Accidents Injuries Act 2017" and replacing them with "section 63 of the Motor Accidents Compensation Act 1999 (NSW)". 2. Order in the nature of certiorari moving into this Court and quashing the certificate of determination of the second defendant dated 26 April 2024 purportedly issued pursuant to s 63(3) of the Motor Accidents Compensation Act 1999 (NSW). 3. Order that the plaintiff's application for review of the certificate of Medical Assessor Home dated 12 April 2023 is remitted to the third defendant for referral to a differently constituted review panel for determination according to law. 4. Order that the first defendant is to pay the plaintiff's costs. ********** DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 10 March 2025