Court of Appeal Supreme Court New South Wales Medium Neutral Citation: Vannini v Worldwide Demolitions Pty Ltd [2018] NSWCA 324 Hearing dates: 8 November 2018 Decision date: 17 December 2018 Before: Macfarlan JA at [1] Gleeson JA at [2] Barrett AJA at [113] Decision: (1) Grant leave to appeal. (2) Direct the appellant to file a notice of appeal in the form contained in the White Book within 7 days. (3) Appeal dismissed. (4) Appellant to pay the first respondent's costs. Catchwords: ADMINISTRATIVE LAW – jurisdictional error – where appellant worker suffered lower back injury – dispute about degree of permanent impairment – where approved medical specialist (AMS) made no deduction for any proportion of impairment due to prior injury and pre-existing condition – appeal by employer on ground of demonstrable error – Appeal Panel revoked certificate and issued new certificate – where 50 percent deduction for proportion of impairment due to prior injury and pre-existing condition – appellant claimed Panel substituted decision of AMS without finding the certificate of assessment contained demonstrable error – Workplace Injury Management and Workers Compensation Act 1998 (NSW), s 327(3)(d) – whether primary judge erred in finding that Panel identified demonstrable error contained in certificate of AMS – whether Panel needed to expressly say certificate contained demonstrable error – whether error found by Panel was "demonstrable error" Legislation Cited: Supreme Court Act 1970 (NSW), s 101(2)(r) Workers Compensation Act 1987 (NSW), s 151H Workers Compensation Legislation Amendment Bill 2001 (No 2) (NSW) Workers Compensation Legislation Amendment Act 2010 (NSW), Sch 2 [14] Workplace Injury Management and Workers Compensation Act 1998 (NSW), ss 319, 321, 322, 322A, 323, 324, 325, 326, 327, 328 Uniform Civil Procedure Rules 2005 (NSW), r 42.1 Cases Cited: Aldi Foods Pty Ltd (ACN 086 210 139) v Morrocanoil Israel Ltd [2018] FCAFC 93; (2018) 358 ALR 683 Bindah v Carter Holt Harvey Woodproducts Australia Pty Ltd [2014] NSWCA 264 Branir Pty Ltd v Owston Nominees (No 2) Pty Ltd (2001) 117 FCR 424; [2001] FCA 1833 Bunnings Group Ltd v Hicks [2008] NSWSC 874 Campbelltown City Council v Vegan [2004] NSWSC 1129 Campbelltown City Council v Vegan (2006) 67 NSWLR 372; [2006] NSWCA 284 Cole v Wenaline Pty Ltd [2010] NSWSC 78 Fox v Percy (2003) 214 CLR 118; [2003] HCA 22 Hossain v Minister for Immigration and Border Protection [2018] HCA 34; (2018) 359 ALR 1 House v The King (1936) 55 CLR 499; [1936] HCA 40 Mahenthirarasa v State Rail Authority of New South Wales [2008] NSWCA 101; (2008) 6 DDCR 61 Merza v Registrar of the Workers Compensation Commission [2006] NSWSC 939 Minister for Immigration and Border Protection v SZVFW [2018] HCA 30; (2018) 92 ALJR 713 Minister for Immigration and Ethnic Affairs v Wu Shan Liang (1996) 185 CLR 259; [1996] HCA 6 Pitsonis v Registrar of the Workers Compensation Commission (2008) 73 NSWLR 366; [2008] NSWCA 88 Plaintiff S157/2002 v The Commonwealth (2003) 211 CLR 476; [2003] HCA 2 Riverina Wines Pty Ltd v Registrar of the Workers Compensation Commission of NSW [2007] NSWCA 149 SAS Trustee Corporation v Miles [2018] HCA 55; (2018) 92 ALJR 1064 Siddik v WorkCover Authority of NSW [2008] NSWCA 116 Versace v Australia's Best Tyres & Auto Pty Ltd [2016] NSWSC 1540 Vitaz v Westform (NSW) Pty Ltd [2011] NSWCA 254 Wingfoot Australia Partners Pty Ltd v Kocak (2013) 252 CLR 480; [2013] HCA 43 Texts Cited: New South Wales Legislative Assembly, Parliamentary Debates (Hansard), 19 June 2001 Category: Principal judgment Parties: Aaron Vannini (Appellant) Worldwide Demolitions Pty Ltd (First Respondent) Workers Compensation Commission of New South Wales (Second Respondent) The Medical Appeal Panel of the Workers Compensation Commission of New South Wales constituted by Arbitrator Deborah Moore, Dr Drew Dixon and Dr Gregory McGroder (Third Respondent) Representation: Counsel: D Hooke SC / N Read (Appellant) J Kirk SC / P Herzfeld (First Respondent) Solicitors: Kells Lawyers (Appellant) Gillis Delaney Lawyers (First Respondent) File Number(s): 2018/167633 Decision under appeal Court or tribunal: Supreme Court of New South Wales Jurisdiction: Common Law Division Citation: [2018] NSWSC 572 Date of Decision: 3 May 2018 Before: Fagan J File Number(s): 2017/293733 [Note: The Uniform Civil Procedure Rules 2005 provide (Rule 36.11) that unless the Court otherwise orders, a judgment or order is taken to be entered when it is recorded in the Court's computerised court record system. Setting aside and variation of judgments or orders is dealt with by Rules 36.15, 36.16, 36.17 and 36.18. Parties should in particular note the time limit of fourteen days in Rule 36.16.] Judgment 1. MACFARLAN JA: I agree with Gleeson JA. 2. GLEESON JA: Mr Aaron Vannini suffered a lower back injury on 6 March 2009 when working as a demolition labourer employed by the first respondent, Worldwide Demolitions Pty Ltd (the Employer). He had suffered an earlier back injury in April 2008 while working for another employer and undergone an operation to his back in August 2008. Notice of Mr Vannini's intention to commence common law proceedings was served on the Employer's insurer in November 2016. A dispute arose about the degree of permanent impairment suffered by Mr Vannini resulting from the 2009 injury and the extent of contribution to such impairment from the 2008 injury. Before proceedings could be commenced it was necessary to determine whether he had suffered a degree of permanent impairment of at least 15 percent. [1] 3. On 11 April 2017, an approved medical specialist, Dr Thomas Rosenthal, issued a medical assessment certificate assessing Mr Vannini's whole person impairment at 22 percent, and determined that no part of this impairment was due to previous injury or pre-existing condition or abnormality. 4. The Employer brought an appeal against the medical assessment certificate to an Appeal Panel. On 31 August 2017, the Panel revoked the certificate issued by Dr Rosenthal and issued a new certificate assessing the degree of permanent impairment at 12 percent. In arriving at that assessment the Panel assessed Mr Vannini's whole person impairment at 24 percent and made a deduction of 50 percent of this impairment because of Mr Vannini's previous injury and pre-existing condition. 5. Mr Vannini brought proceedings by way of judicial review in the Supreme Court challenging the decision made by the Panel on review. Before the primary judge Mr Vannini complained that the Panel had made a jurisdictional error or error of law on the face of the record by substituting its own view for that of the approved medical specialist, Dr Rosenthal, without having found an error of the kind referred to in s 327(3) of the Management Act, relevantly, the assessment was made on the basis of incorrect criteria (s 327(3)(c)) or the medical assessment certificate contains a demonstrable error (s 327(3)(d)). Mr Vannini also complained that the Panel's reasons were inadequate. 6. On 3 May 2018, Fagan J rejected both complaints and dismissed the summons with costs. [2] His Honour found that the determination by the Panel that there should be a 50 percent deduction for the previous injury and pre-existing condition was, in the circumstances, the recognition of a demonstrable error in Dr Rosenthal's medical assessment certificate (which had made no such deduction). 7. Mr Vannini seeks leave to appeal from those orders. The Employer is the only active respondent. Both the Workers Compensation Commission and the Appeal Panel have filed a submitting appearance. 8. Leave to appeal is sought on the basis that the appeal involves a matter at issue amounting to less than $100,000. [3] It is not possible on the materials before this Court to assess the amount of Mr Vannini's damages claim for economic loss, assuming his degree of permanent impairment is at least 15 percent. [4] Nonetheless, given that the proposed appeal concerns the proper construction of the Panel's power on review under s 328 of the Management Act, it is appropriate that there be a grant of leave. 9. For the reasons that follow, the appeal should be dismissed with costs. The assessment of medical disputes under the Management Act 1. Part 7 of Ch 7 of the Management Act deals with the resolution of medical disputes, which includes disputes about "the degree of permanent impairment of the worker as a result of an injury": s 319. The scheme is designed to ensure that the degree of permanent impairment that results from injury, and any contribution to the worker's total impairment that is due to an earlier injury or pre-existing condition, are assessed in accordance with Pt 7 of Ch 7 of the Management Act, and not otherwise. [5] 2. A medical dispute may be referred for assessment under Pt 7 by a court, the Commission or the Registrar, either of their own motion or at the request of a party to the dispute: s 321. 3. The assessment of the degree of permanent impairment of an injured worker is to be made in accordance with the Workers Compensation Guidelines (as in force at the time the assessment is made) issued for that purpose: s 322(1). In assessing the degree of permanent impairment resulting from an injury, there is to be a deduction for any proportion of the impairment that is due to any previous injury or that is due to any pre-existing condition or abnormality: s 323(1). 4. Only one assessment may be made of the degree of permanent impairment of an injured worker: s 322A(1). However, this provision does not affect the operation of s 327 of the Management Act, which deals with an appeal against medical assessment: s 322A(4). 5. The powers of an approved medical specialist are set out in s 324 and include the power to require the worker to submit to examination by the approved medical specialist: s 324(1)(c). These powers extend to the assessment of a medical dispute in the course of an appeal or a further assessment under Pt 7. An approved medical specialist who is the member of the Panel hearing the appeal or who is assessing the matter by way of further assessment has all the powers of an approved medical specialist under s 324 on an assessment of a medical dispute: s 324(3). 6. The approved medical specialist to whom a medical dispute is referred is required to give a certificate as to the matters referred for assessment: s 325(1). The certificate is to be in a form approved by the Registrar (s 325(2)) and is to: (a) set out details of the matters referred for assessment, and (b) certify as to the approved medical specialist's assessment with respect to those matters, and (c) set out the approved medical specialist's reasons for that assessment, and (d) set out the facts on which that assessment is based. 1. An assessment certified in a medical assessment certificate under Pt 7 is conclusively presumed to be correct as to the specific matters in s 326(1) in any proceedings before a court or the Commission with which the certificate is concerned. Relevantly in this case, those matters are the degree of permanent impairment of the worker as a result of an injury: (s 326(1)(a)) and, whether any proportion of permanent impairment is due to any previous injury or pre-existing condition or abnormality (s 326(1)(b)). 2. A right of appeal against a medical assessment under Pt 7 is provided to a party to a medical dispute, but only in respect of an "appealable" matter, and only on specified grounds: s 327(1). A matter is appealable under s 327 if it is a matter as to which the assessment of an approved medical specialist certified in a medical assessment certificate under Pt 7 is conclusively presumed to be correct in proceedings before a court or the Commission: s 327(2). This is a reference back to the matters identified in s 326(1). 3. The grounds of appeal are expressly limited by s 327(3) which provides: (3) The grounds for appeal under this section are any of the following grounds: (a) deterioration of the worker's condition that results in an increase in the degree of permanent impairment, (b) availability of additional relevant information (but only if the additional information was not available to, and could not reasonably have been obtained by, the appellant before the medical assessment appealed against), (c) the assessment was made on the basis of incorrect criteria, (d) the medical assessment certificate contains a demonstrable error. 1. An appeal is made by application to the Registrar, and is not to proceed unless the Registrar is satisfied that, on the face of the application, and in any submissions made to the Registrar, at least one of the grounds for appeal specified in sub-section (3) has been made out: s 327(4). In this regard the role of the Registrar has been described as that of a "gatekeeper", the criterion for the appeal proceeding past the gatekeeper being the opinion of the Registrar that one of the grounds of appeal existed. [6] The amendments to s 327(4) of the Management Act in November 2006 have not altered the role of the Registrar as gatekeeper. [7] 2. An appeal against a medical assessment is to be heard by an Appeal Panel constituted by two approved medical specialists and one arbitrator, chosen by the Registrar: s 328(1). The appeal is to be by way of review of the original medical assessment, but the review is limited to the grounds of appeal on which the appeal is made: s 328(2). There is a restriction on the Panel receiving evidence that is fresh, additional or in substitution for the evidence before the medical assessor unless the evidence was not available to the party before that medical assessment and could not reasonably have been obtained by that party before that medical assessment: s 328(3). 3. The Panel's powers on review are limited to either confirming the certificate of assessment, or revoking the certificate and issuing a new certificate as to the matters concerned, in which event the new certificate has the conclusive status provided by s 326: s 328(5). 4. The nature of an appeal under s 328(2) "by way of review" was considered by this Court in Siddik v WorkCover Authority of NSW. [8] The Court concluded that it was "a novel form of appeal", the legislature having created a flexible model which involves either a hearing de novo (when new evidence is received because of changed circumstances: either a deterioration of the worker's condition or the availability of additional relevant information, subject to the restriction in s 328(3); s 327(3)(a)) and (b), or a re-hearing (which involves identification and correction of error: s 327(3)(c) and (d)). [9] The amendment to s 328(2) in 2010, after the decision in Siddik [10] that limited a Panel's review "to the grounds of appeal on which the appeal is made", [11] does not change the fundamental nature of an appeal under s 328(2) as explained in Siddik. Background 1. According to his statement, in 2008 Mr Vannini was aged 23 years and had been employed by Effective Demolitions in heavy labouring work demolishing buildings for three to four years when he developed a gradual onset of back pain. He gave a history to Dr Rhys Gray, orthopaedic surgeon, in April 2009 that "over the years he had experienced pain with heavier manual work", that in the first half of 2008 he "experienced increasing low back pain with activity" and in April 2008 "there was the onset of specific pain into the right leg, as well as the low back". His condition deteriorated "until he could not maintain his normal duties" with Effective Demolitions. 2. Following radiological investigations of Mr Vannini's lumbar spine in June and July 2008, Dr Ravi Cherukuri recommended a back operation which he performed on 4 August 2008. That involved an L5/S1 laminotomy, micro lumbar diskectomy and foraminotomy on the right side, which the primary judge explained in these terms. [12] Laminotomy is the removal of part of a vertebra, apparently in this case to gain surgical access to the intervertebral disc. Discectomy is the removal of part of a bulging or protruding disc. Here this was evidently done to relieve pressure on nerve roots exiting the spinal column at the L5/S1 level. Foraminotomy is clearing out the foramina, being the passage through the vertebrae in which nerve roots are located, again in this case to relieve contact or pressure of other tissue upon the nerve roots. 1. Mr Vannini returned to work with Effective Demolitions after the 2008 injury and operation, but ultimately left that employment because he had problems with his employer "who would not make allowances for me". 2. At some time in late 2008 or early 2009, Mr Vannini commenced work with the Employer. He said in his statement that his back felt better than it did before the 2008 operation and he was able to do very heavy demolition and labouring work. 3. On 6 March 2009, while lifting a sheet of roofing iron, Mr Vannini felt a sudden severe pain in his lower back and leg pain. He was able to descend the ladder from the roof on which he had been working, but he could not resume work. He was examined by Dr Gray on 27 April 2009 who diagnosed that Mr Vannini had probably suffered an aggravation of a pre-existing condition, being a recurrent disc prolapse at L5/S1 that was initially dealt with in 2008 or possibly the disc above at L4/5 causing a central disc prolapse. An MRI scan of Mr Vannini's lumbar spine performed on 29 April 2009 identified a significant signal abnormality at the L5/S1 with mild mass effect on the S1 nerve root and a L4/5 disc protrusion to be displacing the traversing right L5 nerve root and abutting the left L5 nerve root. 4. Mr Vannini received benefits up to September 2009 when he was medically certified fit for light duties. On 24 January 2012, Mr Vannini lodged a claim for lump sum compensation in respect of the 2009 injury relying upon a report of Dr James Bodel, orthopaedic surgeon, dated 5 July 2010. The 2012 claim by Mr Vannini was resolved between the parties on 29 February 2012 by a Complying Agreement under s 66A of the WC Act, for 5 percent whole person impairment. 5. In his 2010 report, Dr Bodel diagnosed a central and left-sided disc prolapse which he described as a recurrence of the previous disc injury at that level. Dr Bodel considered Mr Vannini had reached the maximum medical improvement and assessment whole person impairment at 15 percent. After acknowledging that apportionment of liability is a very difficult issue, Dr Bodel apportioned approximately two-thirds of the total pathology to the original injury and one-third to the injury on 6 March 2009. 6. According to his statement, Mr Vannini's back pain did not improve over time and in fact got worse up to 2015. On 2 June 2015, Dr Cherukuri performed an L5/S1 posterior lumbar inter-body and posterior lateral fusion. 7. Dr Bodel examined Mr Vannini in August 2016 and issued a report dated 23 August 2016 in which he assessed a 22 percent whole person impairment with no deduction for contribution from pre-accident injury, condition or abnormality. This report made no reference to Dr Bodel's earlier 2010 report. As the primary judge observed: [13] Dr Bodel said in his five-page report of August 2016 that the plaintiff had suffered right-sided leg pain in 2008 but exhibited left-sided disc protrusion on the MRI of 28 April 2009. However he did not identify this as a basis for his change of view. The material before Dr Rosenthal and the Appeal Panel showed that the plaintiff's L5/S1 disc pathology was in fact not limited to the right side in 2008. Dr Bodel's August 2016 reports made no reference to the radiology of June and July 2008 which did not suggest the left side was unaffected. At that time the L5/S1 disc bulge was central and "more prominent to the right". Dr Bodel did not refer to Dr Cherukuri's observation of "bilateral signs and symptoms in the lower extremities" as at 30 July 2008 (see [12]). The material also showed that after 6 March 2009 the L5/S1 pathology was not limited to the right side. In his August 2016 reports Dr Bodel did not refer to the radiology of 1 February 2014 which identified bilateral L5/S1 nerve impingement at that date, nor to the MRI of 13 October 2014 on which there could be seen "post L5/S1 discectomy [ie post the operation of 4 August 2008] a moderate recurrent protruding disc … at this level which is prominent on the right side resulting in right foraminal narrowing and impingement of the right exiting nerve root" (see [25]). 1. On 11 November 2016, Mr Vannini made a further claim for lump sum compensation in respect of the 2009 injury. On 28 November 2016, the insurer denied liability in relation to Mr Vannini's claim for further permanent impairment entitlements. Dr Rosenthal's certificate – 11 April 2017 1. Dr Rosenthal's medical assessment certificate dated 11 April 2017 states that he examined Mr Vannini on 5 April 2017 and obtained a history relating to the 2009 injury and the previous injury in 2008. 2. After summarising Mr Vannini's present symptoms and the details and dates of special investigations, Dr Rosenthal concluded under the heading "Summary of injuries and diagnosis": Mr Vannini sustained a L5/S1 disc injury and recurrent disc protrusion in the injury that occurred on 6 March 2009 at work. He had a previous disc abnormality which had been surgically repaired and apparently had resolved, allowing him to return to work. The 2009 injury appeared to be a new frank injury. He subsequently had a spinal fusion performed as the result of that disc injury by Dr Cherukuri. 1. Under the heading "Evaluation of Permanent Impairment", Dr Rosenthal gave the following response to the question 8(e) (which is included in the approved form of certificate under s 325(2) of the Management Act) (bold in original): Is any proportion of the whole person impairment due to a previous injury, pre-existing condition or abnormality?: The determination as to whether there was a pre-existing condition to warrant a deduction is a difficult one to determine. In reference to [Cole v Wenaline Pty Ltd [2010] NSWSC 78] can be considered a new frank injury and unrelated to the 2008 injury which had been surgically repaired. In this case the repaired disc protrusion from 2008 would be considered to have resolved, and then a new disc protrusion occurred from the 2009 injury which would not be considered to be an aggravation or extension of the 2008 injury. Thus in reference to [Cole v Wenaline Pty Ltd] the injury does not warrant a deduction. Based on this information I believe that no deduction should be applied. 1. Under the heading "Reasons for Assessment", Dr Rosenthal assessed 22 percent whole person impairment with no deduction under s 323 of the Management Act for any proportion of the impairment that was due to any previous injury. In making that assessment, Dr Rosenthal stated that he had taken into account the history, examination findings, radiology and medical reports. 2. In the same part of the reasons, Dr Rosenthal gave the following response to question 10(c) in the approved form of certificate (bold in original): My brief comments regarding the other medical opinions and findings submitted by the parties and, where applicable, the reasons why my opinion differs. Of particular interest is the report of Dr Bodel, who assessed Mr Vannini on 05/07/2010. At that stage he had not had his surgical fusion [Dr Cherukuri's operation of 2 June 2015] but he was classified as DRE III and then he apportioned the impairment based on a recurrence of his old injury in 2008. However, under the rules of apportionment the old injury would have had to be contributing to his current impairment and Dr Bodel has not established such a contribution in his report. Indeed when he gave his next report on 23/08/2016 he assessed 22% WPI for the fusion and activities of daily living. This time Dr Bodel determined there was no deduction for pre-existing impairment. He did not elaborate on why he has changed his view from his 2010 assessment. … Dr Gray noted that he essentially recovered from his 2008 surgery before having the new injury in 2009, but he considered that [the plaintiff] had probably suffered an aggravation of the pre-existing condition. He then thought that the new injury was related to the L4/5 disc but did not have the latest MRI at the time of his assessment. … The Employer's appeal 1. In its application to appeal against the decision of the approved medical specialist filed 5 May 2017, the Employer indicated by marking the box next to two of the four possible grounds of appeal under Pt 3 – Grounds of Appeal that two grounds were relied on: namely, the assessment was made on the basis of incorrect criteria, and the medical assessment certificate contains a demonstrable error. 2. In this regard, it should be observed that the approved form (Form 10) issued by the Commission does not require any specificity of the nature of the alleged errors the subject of those appeal grounds. While Pt 4 of the approved form provides for the attachment of supporting documentation, including submissions detailing the grounds of appeal, the absence of any requirement in the approved form to precisely and properly identify the nature of the ground(s) of appeal under s 327(3) of the Management Act renders more difficult the task of the Registrar as the gatekeeper under s 327(4) and the task of an Appeal Panel on review under s 328 in considering the nature of the alleged errors. 3. In this case, the Employer's submissions attached to the application to appeal stated under the heading "Demonstrable error": [27] The appellant submits in view of the application of incorrect criteria the MAC contains a demonstrable error in that it incorrectly refers to impairment assessments which have not been derived on a correct basis and in accordance with AMA 5 and the WorkCover Guides. 1. That may be taken to be a reference to the Employer's earlier submissions under the heading "Incorrect criteria", which relevantly contended that the approved medical specialist had fallen into the same error as Dr Bodel in his 2016 report in that: * the fact Mr Vannini made a good recovery following the surgery (in 2008) is not a basis to not provide a deduction as Dr Bodel previously made for pre-existing impairment in his 2010 report (par 16); * there is no reasoning by the approved medical specialist why the 2009 injury could be considered a new frank injury and unrelated to the 2008 injury noting the previous opinion of Dr Bodel in 2010 (par 21); * Dr Bodel did not elaborate on why he changed his view (in his 2016 report) from his 2010 assessment (par 22); * In view of the clear medical evidence of pre-existing condition or abnormality which directly contributes to the impairment of the lumbar spine, a two-thirds deduction is appropriate pursuant to s 323 of the Management Act, as previously assessed by Dr Bodel in his 2010 report (par 23). The Appeal Panel's reasons – 31 August 2017 1. As indicated, the Panel's certificate dated 31 August 2017 revoked the certificate given by Dr Rosenthal and issued a new medical assessment certificate assessing 12 percent whole person impairment taking into account a 50 percent deduction of permanent impairment due to pre-existing injury, abnormality or condition. 2. In its reasons, the Panel noted that it had determined that it was not necessary for Mr Vannini to undergo a further medical examination, [14] and that it had before it all of the documents that were sent to the approved medical specialist for the original assessment and had taken them into account when making its determination. [15] 3. The Panel summarised the parties' competing submissions. [16] The Employer submitted that the approved medical specialist failed to make any deduction pursuant to s 323 of the Management Act in circumstances where "there was ample evidence of a pre-existing condition which contributed to the impairment", and Mr Vannini submitted that no errors were made. 4. The Panel acknowledged [17] that the appeal is to be by way of review of the original medical assessment, but the review is limited to the grounds of appeal on which the appeal is made. It had earlier noted [18] that the appeal grounds were those referred to in the Management Act, s 327(3)(c) (incorrect criteria) and (d) (demonstrable error). 5. The Panel then proceeded to summarise the reasoning of the approved medical specialist, including on the question of impairment due to pre-existing injury and the way in which the approved medical specialist had dealt with the first report of Dr Bodel dated 5 July 2010 and his later report of 23 August 2016, noting the unexplained change of opinion reflected in Dr Bodel's later report, in particular: [19] * Dr Bodel first saw Mr Vannini on 5 July 2010, the date of his report, and obtained a history of the 2008 injury and the 2009 injury (as referred to at [28]-[29] above) and stated that "[t]he MRI of the lumbosacral spine on 27 July 2008 confirms the large right-sided disc prolapse at the L5/S1 level and the central bulging at L4/5"; * Dr Bodel noted that a CT-scan and MRI in July 2008 both showed a central disc bulge at the L4/5 level and a right-sided disc prolapse at L5/S1, and in relation to the MRI scan of 28 April 2009, Dr Bodel observed: There is the same central bulging at the L4/5 level and there has been a recurrence of the disc prolapse at the L5/S1 level and this is more to the left-hand side although it is centrally and slightly right-sided as well; Dr Bodel continued: He has subsequently had a recurrence of that injury on 6 March 2009 while employed with a new employer. … There is a definite difference in the appearance of the abnormality at the L5/S1 level in the two MRI scans … and therefore an additional structural injury has occurred at the time of the second work injury … [he] has had a recurrent disc prolapse at the lumbosacral junction as a result of [the second injury] …; * after assessing Mr Vannini's whole person impairment at 15 percent, Dr Bodel added (in his 2010 report): Apportionment of liability is a very difficult issue. [He] clearly had a previous work-related injury which led to a decompressive surgical procedure. He has had a recurrence of that injury. … I would apportion approximately two-thirds of the total pathology to the original injury and one-third to the injury on 6 March 2009. In reality the pathology is all the same pathology although there has been a further 'injury' which has changed the underlying pathology which had been achieved after the decompressive surgery; * Dr Bodel saw Mr Vannini on a second occasion on 19 August 2016 and prepared a report dated 23 August 2016, noting that Mr Vannini had slowly deteriorated since July 2010 and had undergone "posterior fusion in the lumbosacral region with pedicle screws and rods and an interbody fusion". After referring to some radiological material, Dr Bodel added: The diagnosis here is a disc rupture at the lumbosacral junction. The initial date of injury for this accident is 6 March 2009. He had a previous injury at the same level for which he had appropriate decompressive surgery. He was relatively asymptomatic at the time of the injury on 6 March 2009 and therefore a new 'injury' occurred at that level at that time; * after assessing Mr Vannini's whole person impairment at 23 percent, Dr Bodel observed (in his 2016 report): I am aware that this gentleman has had a previous injury in 2008 and previous surgery. He made a good recovery and had returned to normal heavy physical work prior to this injury … in this circumstance therefore there is no basis for a deduction for pre-existing impairment. * Dr Bodel did not provide any explanation for his change of opinion. 1. The Panel identified [20] (it is common ground, correctly) the way in which the question of contributory causation posed by s 323 of the Management Act is to be assessed, by reference to relevant authorities. First, it would be "an error to proceed on the basis that once a person has had surgery to the lumbar spine, irrespective of the outcome, that person has a residual level of impairment" and that what is required is "a conclusion based on all the evidence, that the pre-existing injury, condition or abnormality caused or contributed to that impairment". [21] Second, "if a pre-existing condition is a contributing factor causing permanent impairment, a deduction is required even though the pre-existing condition had been asymptomatic prior to the injury". [22] 2. After stating its conclusion that "… we are of the view that [Mr Vannini's] injury in 2008 did contribute to the current level of impairment", [23] the Panel gave the following reasons why it reached a different conclusion from the approved medical specialist on the question of impairment due to previous injury and pre-existing condition: 43. To begin with, the report of Dr Bodel of 5 July 2010 clearly indicated that "in reality, the pathology is all the same pathology" although he accepted that "an additional structural injury has occurred at the time of the second work injury …". 44. The radiological investigations certainly indicate to us that the [plaintiff] sustained an injury in March 2009 at the same level. As Dr Bodel noted, he had "a recurrence" of the 2008 injury in March 2009. 45. The treating surgeon, Dr Cherukuri, has not really addressed this issue - his reports essentially document the treatment he provided. 46. Dr Gray saw the [plaintiff] at the request of the insurer on 27 April 2009. In a report of the same date, he concluded that he "has probably suffered an aggravation of a pre-existing condition … this present exacerbation may represent a recurrent disc prolapse at the same level (L5/S1) that was initially dealt with in 2008 …". Dr Gray did think there may have been a further new injury at the L4/5 level but as [Dr Rosenthal] noted, "he did not have the latest MRI at the time of assessment". 47. In short, in our view there was ample evidence that the injury in March 2009, only some seven months after the earlier injury and surgery, and at the same level, contributed to the current impairment. The consensus of medical opinion suggested that the 2009 injury represented a "recurrence" of the earlier injury, although we accept that some additional impairment arose after the 2009 injury which led to a spinal fusion and impacted his activities of daily living. 48. Dr Bodel's opinion is flawed to the extent that he has simply not explained his reasons for changing his opinion, and in these circumstances, it is difficult for us to reconcile the competing opinions. 49. Although we accept that the [plaintiff] felt that he had recovered well from the 2008 surgery, and was apparently asymptomatic at the time of the 2009 injury, that of itself is not necessarily sufficient to exclude a deduction. (See Vitaz). 50. The evidence seems clear that the [plaintiff] suffered from discal instability after the 2008 surgery. Any interference with a disc will produce that result. Moreover, the recurrence occurred within a fairly short time. 51. For these reasons, and having carefully considered all of the evidence, we are of the view that a one-half deduction in this case is appropriate. The grounds of the application for judicial review before the primary judge 1. In his amended summons filed 25 October 2017 Mr Vannini relied on eight grounds asserting jurisdictional error and/or errors of law on the face of the record. It is only necessary to refer to grounds 1-4 and 8 which are relevant to the appeal to this Court. 2. As the primary judge observed, [24] grounds 1-4 collectively alleged that the Panel "substituted its own view for that of [Dr Rosenthal]" without having found error of the kinds referred to in pars (c) or (d) of s 327(3) of the Management Act, that is, without finding that Dr Rosenthal's assessment was made on the basis of incorrect criteria or that it contained a demonstrable error. 3. Ground 8 alleged that the Panel had failed to give adequate reasons for its decision. 4. Before turning to the primary judge's reasons it is of assistance to say something about jurisdictional error. Jurisdictional error 1. In Hossain v Minister for Immigration and Border Protection, [25] the plurality in the High Court explained the terminology of jurisdictional error as follows (citations omitted): [26] Jurisdictional error, in the most generic sense in which it has come to be used to describe an error in a statutory decision-making process, correspondingly refers to a failure to comply with one or more statutory preconditions or conditions to an extent which results in a decision which has been made in fact lacking characteristics necessary for it to be given force and effect by the statute pursuant to which the decision-maker purported to make it. To describe a decision as "involving jurisdictional error" is to describe that decision as having been made outside jurisdiction. A decision made outside jurisdiction is not necessarily to be regarded as a "nullity", in that it remains a decision in fact which may yet have some status in law. But a decision made outside jurisdiction is a decision in fact which is properly to be regarded for the purposes of the law pursuant to which it was purported to be made as "no decision at all" . To that extent, in traditional parlance, the decision is "invalid" or "void". 1. The plurality also emphasised in Hossain [27] that "jurisdictional error is an expression not simply of the existence of error but of the gravity of that error", before stating the judicial method by which jurisdictional error is to be ascertained: [28] … The question of whether a particular failure to comply with an express or implied statutory condition in purporting to make a particular decision is of a magnitude which has resulted in taking the decision outside the jurisdiction conferred by the statute cannot be answered except by reference to the construction of the statute. The primary judge's reasons 1. The primary judge found that grounds 1-4 involved a misapprehension, namely that they treated the Panel's finding that the previous injury and disc degeneration were 50 percent causative of Mr Vannini's impairment, in substitution for Dr Rosenthal's finding of nil contribution, as if this was something different from the resolution of the appeal ground. The primary judge continued: [29] The true position is that substitution by the Appeal Panel of its factual finding of 50% contribution is, of itself, the identification of error of fact on the part of Dr Rosenthal. As discussed below, it is relevant to consider whether this successful ground of appeal fits either of the generic descriptions in pars (c) or (d). But that is a matter of classification of the successful ground, not of identifying additional or collateral errors. On the issue of contributory causation of impairment, that which the plaintiff refers to as the "substitution of [the Panel's] own view" on the evidence is, far from being in excess of the Panel's power, just another way of describing the Panel's determination that Dr Rosenthal's finding on the evidence was an error of fact, thereby upholding the appeal. 1. The primary judge found [30] that the sole challenge to Dr Rosenthal's decision which was considered and upheld by the Panel related to the erroneous finding of nil contributory causation from the 2008 L5/S1 disc injury and pathology and this ground was not within par (c) of s 327(3) (incorrect criteria), but it was within par (d) (demonstrable error). His Honour characterised the asserted demonstrable error in the following terms: [31] … what was involved in this appeal was an asserted erroneous finding of fact (namely, the causative effect of the previous accident and pre-existing pathology) … 1. The primary judge then turned to the concept of "demonstrable error". After referring to the remarks of this Court in Pitsonis, [32] the primary judge found [33] that Dr Rosenthal's reasons incorporated in his medical assessment certificate, taken together with the reports and other materials in the referral of the dispute to him, demonstrated on their face what his conclusion was and the evidence which either justified it or did not. His Honour continued: [34] … Thus, his error in finding nil contributory causation by previous accident or prior condition, if error the Panel should find it to have been, was demonstrable in the sense expounded by Mason P. For an error to be demonstrable within this meaning it is not necessary that it should be so self-evident that no consideration of the evidence, no reasoning or no application of clinical judgment is required. If par (d) were intended to limit the appellability of findings of fact as tightly as that, it would hardly be necessary for a ground under (d) to be considered by a Panel comprising two medical experts. 1. In rejecting Mr Vannini's contention that the Panel had substituted their own preferred view on the factual question of contributory causation without finding relevant error by Dr Rosenthal, the primary judge reasoned that this argument set up a false dichotomy between an appellate body coming to a different conclusion from that of the primary decision-maker on an issue of fact which constitutes an appeal ground, and the appellate body finding appealable factual error. His Honour found: [35] The Appeal Panel's conclusion on the evidence, contrary to that of the primary decision maker, is the finding of factual error. There is no more for the Panel to say about why or how the primary decision-maker erred than to state (as they did) adequate reasons for coming to their own substituted conclusion of fact. 1. After referring to the conclusions of McColl JA in Siddik [36] regarding the nature of the appeal under s 328 and noting that s 328(2) had been subsequently amended, the primary judge accepted that an appeal to the Panel in a case such as the present "has indicia of an appeal by way of rehearing" and noted the importance of the medically-qualified Panel members being able to decide questions of fact within their expertise remain pertinent following the amendment to s 328(2). [37] 2. The primary judge also referred [38] to the manner in which other appellate tribunals proceed by way of rehearing with respect to a ground of error of fact and the extent to which an appellate court should recognise advantages in fact-finding enjoyed by a first instance judge discussed in Fox v Percy. [39] His Honour considered that no such advantages are enjoyed by an approved medical specialist relative to an Appeal Panel when the appeal concerns "demonstrable error" of fact in s 327(3)(d) and that in such a case the Panel is on an equal footing with the approved medical specialist. [40] 3. As to ground 8 (adequacy of reasons), the primary judge noted that the Panel was subject to an implied statutory obligation to give reasons [41] and referred to the observations of Basten JA in Campbelltown City Council v Vegan [42] concerning the standard which such reasons must meet. [43] After applying that criteria to the Panel reasons, the primary judge concluded [44] that the Panel's reasoning to the conclusion of a 50 percent contribution is sufficiently explained in its reasons [45] (which are set out at [51] above). Issues on appeal 1. The draft notice of appeal contains four grounds. Grounds 1, 2 and 3 concern the power of the Appeal Panel on review under ss 327 and 328 of the Management Act. 2. Grounds 1 and 2 contend that the primary judge erred in construing s 327(3) of the Management Act as permitting an Appeal Panel to review a medical assessment certificate on the merits, without identifying error by the approved medical specialist. Ground 3 contends that the primary judge erred in finding that the Panel found that the medical assessment certificate issued by Dr Rosenthal contains a "demonstrable error" within the meaning of s 327(3)(d) of the Management Act. 3. Ground 4 is connected with the other grounds. It contends that the primary judge erred in finding that the Panel gave adequate reasons for its decision. Senior counsel for Mr Vannini acknowledged that this ground most probably fails, if the other grounds of appeal fail. [46] The parties' submissions Mr Vannini 1. Mr Vannini's submissions commenced with the proposition that identification of error within a specified and permissible ground of appeal under s 327(3) of the Management Act is a jurisdictional pre-condition to the Panel revoking a medical assessment certificate. According to the submission, a Panel is not authorised to simply substitute its opinion for that of an approved medical specialist. 2. Three things should be said immediately about this submission. First, as explained in Siddik, not all of the grounds of appeal in s 327(3) are error based. Two of the grounds – s 327(3)(a) and (b) – involve a hearing de novo (when new evidence is received because of changed circumstances: either a deterioration of the worker's condition or the availability of additional relevant information, subject to the restriction in s 328(3)). Second, it is not in dispute that an appeal based on the ground of "demonstrable error" is error-based. [47] Thus, in a case such as the present where the Panel did not receive new evidence, its role on appeal was to deal with and correct alleged error raised by the appeal. Third, the proposition that the Panel cannot substitute its own view for that of the approved medical specialist requires qualification, namely "absent a finding of error of the kind alleged on the appeal". [48] 3. Mr Vannini next submitted that the primary judge erred in finding that the Panel had performed the task of identifying error and resolving the appeal grounds by coming to a different opinion to the approved medical specialist. The submission continued that the Panel's reasons did not identify any error in the approved medical specialist's certificate, beyond Dr Rosenthal having a different opinion to the Panel. 4. In support of this contention, Mr Vannini drew attention to the Panel's conclusion being expressed in terms of its "view", which it was submitted, was not the resolution of an appeal ground, but a difference of opinion about which reasonable minds may differ. 5. Mr Vannini also submitted that the primary judge erred in his approach to the concept of "demonstrable error". It was submitted that a demonstrable error is one that is obvious or clear from the face of the medical assessment certificate, and not one that requires the examination and forensic evaluation, with clinical expertise, of the evidence underlying the approved medical specialist's reasoning. 6. As to the reasons ground, Mr Vannini submitted that the primary judge engaged in a reverse merits review by providing the reasons that the Panel did not give and that demonstrated an absence of adequate reasons on the part of the Panel. [49] The Employer's submissions 1. The Employer emphasised that s 327(3)(d) does not state by reference to what material an error can be demonstrated, but accepted that some limitation is meant to be imposed by use of the adjective "demonstrable". 2. In oral argument, the Employer submitted that the error must be material and must be apparent in findings of fact or reasoning contained in the medical assessment certificate, although the error may be established in part by reference to materials that were before the approved medical specialist and by reference to submissions, but without taking account of fresh or new evidence. It was also submitted that the Panel should make due allowance for any natural advantages of the approved medical specialist not held by the Panel in a way analogous to the approach in Fox v Percy. [50] 3. In writing the Employer accepted that a "demonstrable error" is to be distinguished from a difference of view between the approved medical specialist and the Panel on a point which was reasonably open to differences of view. In oral argument, the Employer submitted that a demonstrable error would probably not extend to issues which are highly dependent on matters of degree or impression, but it was not necessary to decide this issue given, according to the submission, the approved medical specialist's process of reasoning to reach a conclusion on causation attracts the correctness standard of appellate review, rather than tolerates a range of outcomes, [51] referring by analogy to the differing standard of review by appellate courts discussed in Minister for Immigration and Border Protection v SZVFW. [52] 4. As to the adequacy of the Panel's reasons, the Employer submitted that the Panel explained why it reached a different conclusion from the approved medical specialist on the question of impairment due to pre-existing injury by identifying material that was in glaring conflict to the approved medical specialist's conclusion on that point, with which the approved medical specialist simply did not deal and, it was submitted, gave no real reasons on the point. 5. Before turning to the grounds of appeal it is convenient first to address the concept of demonstrable error. The concept of demonstrable error 1. The starting point for ascertainment of the meaning of a statutory provision is the text of the provision considered in light of its context and purpose. [53] Further, where the text read in context permits of more than one potential meaning, the choice between those meanings may ultimately turn on an evaluation of the relative coherence of each with the scheme of the statute and its identified objects or policies. [54] 2. The effect of the statutory scheme outlined above is that the Panel had to determine the appeal brought from the medical specialist's assessment, in accordance with the limitations imposed upon it by that scheme. Commencing with the text, there are two significant limitations for present purposes. First, although the expression "demonstrable error" is not defined in the Management Act, the use of the qualifying word "demonstrable" in a gateway provision such as s 327 may be taken as intended to convey the degree of strictness of scrutiny to which the decision of the approved medical specialist may be subjected. [55] In this regard it has been said that error alone is not sufficient [56] and that such an error must be "material" [57] . Both of those statements accord with the context of the limited right of appeal under s 327. In Pitsonis, Mason P described the "appeal" to the Panel as: [58] … not intended as the opportunity for an application on the basis of fresh evidence tendered without any constraint and/or on the basis of no more than the Appeal Panel being invited to decide the application afresh. … 1. Second, s 327(3)(d) requires that such an error be "contained" in the certificate; that is, the error must be apparent in the certificate of the approved medical specialist. [59] Importantly however, there is no express limitation on the material to which the Panel may have regard when assessing whether the certificate "contains" a demonstrable error. 2. In Merza [60] , which involved a challenge to the Registrar's decision under s 327(4) to refuse an application to appeal from the decision of an approved medical specialist, Hoeben J considered it was sufficient that a demonstrable error is one "readily apparent from an examination of the medical assessment certificate". However, as Basten JA observed in Mahenthirarasa v SRA, [61] that may not constitute a necessary element of the statutory formulation in s 327(3)(d). 3. Pitsonis involved the task of the Registrar under s 327(4) in reaching the required state of satisfaction that an arguable case of error appeared on the face of the certificate. Mason P said [62] (emphasis added): I am therefore driven to conclude that s 327(3)(d) uses "contained" in the more intense meaning of having as a constituent part, comprising or including (Macquarie Dictionary). Thus understood, the paragraph requires the would-be appellant to demonstrate to the Registrar that there is an arguable case of error appearing on the face of the Certificate. It may be an error of fact or law, but it must be more than one that depends upon evidence that is not within s 327(3) (a) or (b) being adduced in the appeal. This conclusion accords with that reached by Hoeben J in Merza v Registrar of the Workers Compensation Commission [2006] NSWSC 939 at [39] ("an error which is readily apparent from an examination of the medical assessment certificate and the document referred the matter to the AMS for assessment".) 1. The parties advanced competing submissions as to the meaning of the third and fourth sentences of Mason P's remarks in the passage quoted above. Mr Vannini submitted that the "referral document" mentioned in Merza is not the entirety of the information referred to the approved medical specialist, but only the pro forma document issued by the Commission requesting the assessment. The Employer responded by emphasising that s 327(3)(d) does not state by reference to what material an error can be demonstrated, and submitted that the "referral document" mentioned in Merza included the whole of the materials before the approved medical specialist. 2. The remarks in Merza and Pitsonis should not be read out of context. The context of those cases was the Registrar's state of satisfaction required under s 327(4) to refer the application to appeal to an Appeal Panel. In particular, what range of material should the Registrar consider when performing the role of gatekeeper? Mason P plainly accepted that the Registrar could look outside the certificate of the medical specialist, but agreed to the limitation suggested by Hoeben J in Merza. It seems to me that read in context, the "referral document" to which Hoeben J likely intended to refer was the document issued by the Commission requesting the assessment. That document would identify for the Registrar the task of the medical specialist to which the matter had been referred for assessment. 3. Nonetheless, this case does not turn on what was intended by the reference to the "referral document" in Merza and Pitsonis. The Registrar's satisfaction as gatekeeper under s 327(4) whether to refer the application to an Appeal Panel is not the same as a Panel's finding on review that a certificate contains a demonstrable error. The former looks to the capacity of the appeal ground being made out, that is, an arguable case of error. The latter looks to the determination of an Appeal Panel whether such an error has been demonstrated. 4. Given the gateway function of the Registrar under s 327(4), it is not surprising that in Pitsonis Mason P referred with approval to the suggested limitation in Merza on the range of material to which the Registrar may have regard when performing that function. Of course, the Registrar is required to consider the application to appeal and any submissions: s 327(4). But the remarks of Mason P and Hoeben J are not determinative of the present case. Accepting that the error must be apparent on the face of the certificate, those remarks say nothing about the range of material to which an Appeal Panel may have regard when determining the correct view of the matter on a rehearing under s 328. 5. The purpose of limiting the grounds of appeal, relevantly, to demonstrable error, may be taken to reflect an intention to provide a limited safety valve for the parties in the case of error by an approved medical specialist, given that the certificate is conclusively presumed to be correct as to the specific matters in s 326(1) in any proceedings before a court or the Commission, subject to the power of an Appeal Panel under s 328(5) to revoke and issue a new certificate, whereupon the presumption in s 326 applies to the new certificate. 6. That a demonstrable error must be apparent in findings of fact or reasoning contained in the medical assessment certificate, although the error may be established in part by reference to materials that were before the approved medical specialist, is consistent with the tentative remarks of Basten JA in Mahenthirarasa v State Rail Authority of New South Wales: [63] The concept of "demonstrable error" is not defined, and may be open to various interpretations, ranging from the broad to the narrow. At the narrowest end of the spectrum, it may be thought that the error must be apparent from reading the certificate itself, thus equating the error with error "on the face of the record" for the unrelated purpose of relief in the nature of certiorari. There is no obvious reason why such a construction should be adopted when the purpose is review on the merits, rather than review for legal error. The word "demonstrable" does not in any event import such a constraint. As noted at [37] above, the example given in the second reading speech suggested that the error must be a manifest error. 1. On the other hand, it is not in dispute that an error is not demonstrable merely because the Panel disagrees with the opinion of the approved medical specialist. That accords with the example given in the second reading speech relating to the Workers Compensation Legislation Amendment Bill 2001 (No 2) (NSW), by which s 327 was introduced into the Management Act, as follows: A demonstrable error would essentially be an error for which there is no information or material to support the finding made – rather than a difference of opinion [64] . 1. One further matter should be mentioned. It concerns the process of identification of error by an Appeal Panel. 2. In the case of an appeal by way of rehearing before an appellate court, error is demonstrated where it is shown that some aspect of the trial judge's reasoning is wrong. How the reasoning may be shown to be wrong depends on what the reasoning is about. [65] For example, whether the challenge is to findings of fact or law or an evaluative judgment, or credit based findings. Appellate courts have developed well established principles which address the approach to the correction of such errors, including the deference shown to the reasons of the trial judge. 3. An Appeal Panel performing the function of administrative review by way of a rehearing is confronted with similar issues when correcting error, particularly when the ground of appeal is demonstrable error contained in the certificate of the medical specialist. It is not necessary to consider how the reasoning of the approved medical specialist may be shown to wrong in every respect. In this case, the Panel was considering the reasoning of the medical specialist on the question of causation arising under s 323. The relevant issue was whether any proportion of the impairment was due to any previous injury, or pre-existing condition or abnormality? If so, what was that proportion? 4. The first question involved an assessment by the Panel, substantially of fact by reference to the evidence, although in part informed by the exercise of a clinical judgment. Such an assessment may be characterised as an evaluative judgment or conclusion based on findings of fact. Nonetheless, the legal criterion applied to reach that conclusion on causation demands a unique outcome, rather than tolerates a range of outcomes. Accordingly the reasoning and finding of the medical specialist attracts the correctness standard of review by a Panel [66] . 5. The position may be different in relation to the second question. A finding as to the proportion of permanent impairment due to previous injury, pre-existing condition or abnormality involves matters of degree and impression. The applicable standard of the "proportion" of contributory contribution under s 323 permits some latitude of opinion such as to admit of a range of legally permissible outcomes. That is not to say that such a conclusion is necessarily beyond review by an Appeal Panel on the ground of demonstrable error. However, the resolution of that question should be left to a case where it is dispositive. Grounds 1 and 2 1. Grounds 1 and 2 are related. They raise the issues of whether the Panel found error in what the approved medical specialist had done in not making any deduction under s 323(3) for any previous injury, pre-existing condition or abnormality, and if so, whether the Panel need expressly say that the certificate contains a demonstrable error? Did the Appeal Panel find error in what the approved medical specialist had done in not making a deduction under s 323? 1. In approaching this question it is important to keep in mind that the reasons of the Panel under challenge must be read as a whole, considered fairly and without "combing through the words with a fine appellate tooth-comb, against the prospect that a verbal slip will be found warranting the inference of an error of law". [67] 2. The Panel's dispositive reasons for concluding that a deduction should be made under s 323 are set out at [48] above. Those reasons are to be read in context. The Panel had earlier noted the reasons given by the approved medical specialist for finding that the 2009 injury was a new frank injury and unrelated to the 2008 injury, namely that injury had been surgically repaired and could be considered to have resolved given that Mr Vannini's condition was asymptomatic. Against that reasoning, the Panel gave seven reasons why the correct conclusion on the relevant evidence was that Mr Vannini's previous injury and pre-existing condition did contribute to the current level of permanent impairment, namely: * First, Dr Bodel had clearly indicated in his 2010 report that "in reality, the pathology is all the same pathology", although he accepted that an additional structural injury had occurred. * Second, the 2009 injury was at the same level as the 2008 injury. * Third, Dr Gray concluded in April 2009 that Mr Vannini "probably suffered an aggravation of a pre-existing condition, relevantly a recurrent disc prolapse at the same level (L5/S1)". And, insofar as Dr Gray thought that there may have been a further new injury at the L4/5 level, he did not have the latest MRI at the time of that assessment: see [27] above. * Fourth, the 2009 injury was only seven months after the earlier injury and surgery and at the same level, and the consensus of medical opinion was that the 2009 injury represented a "recurrence" of the earlier injury, while some additional impairment arose after the 2009 injury. * Fifth, and related to the previous point, the only contrary medical opinion – the 2016 report of Dr Bodel – can be put aside as it is flawed in not explaining the reasons for the change of opinion from his 2010 report. * Sixth, that Mr Vannini was asymptomatic at the time of the 2009 injury is not sufficient to exclude contributory causation in relation to the earlier injury. (Thus, the Panel identified a Vitaz error in the approved medical specialist's reasons insofar as he found no contributory causation under s 323 because Mr Vannini's condition following the 2008 surgery was asymptomatic). * Seventh, Mr Vannini suffered discal instability given the 2008 injury and surgery, and the recurrence occurred within a short time. 1. Having reached the conclusion (contrary to the approved medical specialist) that a deduction should be made under s 323, the Panel turned to its assessment of the proportion of permanent impairment that was due to the previous injury and pre-existing condition. Plainly, that assessment involved a clinical judgment by the Panel based on the relevant evidence identified in its seven reasons referred to above. The complaint by Mr Vannini that the finding by the Panel of 50 percent contribution under s 323 was based on factual findings that were not stated by the Panel, [68] should be rejected. 2. On a fair reading of the Panel's reasons, the Panel did not simply express a different opinion to the approved medical specialist. The Panel implicitly found error on the part of the approved medical specialist in concluding in his certificate that no deduction should be applied under s 323 of the Management Act. 3. Ground 1 is not made out. Whether the Appeal Panel need expressly say the medical assessment certificate contains a demonstrable error? 1. The next complaint by Mr Vannini is directed to the terms in which the Panel expressed its conclusion as its "view", rather than in terms of "demonstrable error". However, this assumes that on an appeal by way of rehearing a reviewing tribunal must express its finding of error in some fixed or formulaic way. I do not agree. To uphold that complaint would be contrary to the admonition in Minister for Immigration and Ethnic Affairs v Wu Shan Liang [69] that a different mode of expression of decision may be expected of a decision made by a person with different, non-legal, expertise. 2. When the Panel came to review the conclusion of the approved medical specialist on the issue of contributory causation, the error was apparent to the Panel because the conclusion that had been reached by the approved medical specialist involved a false step. The approved medical specialist had overlooked relevant matters: the discal instability arising from the 2008 injury and surgery, and the recurrence occurred within a short time; the consensus of medical opinion was that the 2009 injury represented a "recurrence" of the earlier injury, while some additional impairment arose after the 2009 injury; and had taken into account an extraneous consideration which ought not to have been, the Vitaz error, namely that Mr Vannini was asymptomatic at the time of the 2009 injury is not sufficient to exclude contributory causation in relation to the earlier injury. 3. The Panel's conclusion on contributory causation that 50 percent of Mr Vannini's impairment was due to the previous injury and pre-existing condition, implicitly involved a finding of demonstrable error by the approved medical specialist who found to the contrary and did not make any deduction under s 323 of the Management Act. 4. Ground 2 is not made out. Ground 3 Whether the error found by the Appeal Panel answered the description of a "demonstrable error"? 1. The error found by the Panel as to what the approved medical specialist had done in not making a deduction under s 323 for contributory causation to Mr Vannini's permanent impairment due to the previous injury and pre-existing pathology answered the description of a demonstrable error. 2. The error was plainly material to the assessment of Mr Vannini's permanent impairment: 22 percent as per the approved medical specialist's assessment or 12 percent as per the Panel's assessment. The error was capable of being demonstrated and the Panel so found by reference to the relevant evidence before the approved medical specialist. The error was also apparent from an examination of the certificate in the sense referred to in Pitsonis. The nil deduction by the approved medical specialist under s 323 of the Management Act was a constituent part of the certificate issued by the approved medical specialist. 3. Two further matters should be mentioned. 4. First, contrary to Mr Vannini's submissions, the Panel did not fail to give due deference to the advantage the approved medical specialist enjoyed having examined and interviewed Mr Vannini. As mentioned, the only reasons given by the approved medical specialist for his conclusion that no deduction was required under s 323 is that the 2008 injury had been surgically repaired and could be considered to have resolved given that Mr Vannini's condition was asymptomatic. Those reasons did not derive from any advantage over the Panel by reason of having examined Mr Vannini. 5. Second, the submission by Mr Vannini in writing (which was not pressed in argument) that the question of any deduction under s 323 of the Management Act is a matter squarely within the clinical judgment of an approved medical specialist, and is not one that is capable of being described as an error of fact or as a matter of demonstrable error, cannot be accepted in those terms. That submission conflates an error by an approved medical specialist in finding (or not finding) any contributory causation under s 323, with an error in finding the proportion of permanent impairment due to previous injury, pre-existing condition or abnormality: see [91] – [92] above. 6. Ground 3 is not made out. Ground 4 – adequacy of reasons 1. As noted above, Mr Vannini accepted that ground 4 most probably fails if the other grounds of appeal fail. That concession was properly made. 2. It is apparent from the seven reasons given by the Panel as summarised above that the Panel gave sufficient reasons for concluding, contrary to the approved medical specialist, that the previous injury and pre-existing condition contributed to Mr Vannini's current impairment, thereby implicitly finding that the medical assessment certificate contained a demonstrable error. Those reasons explained the actual path of reasoning by which the Panel in fact arrived at the opinion it in fact formed on the medical question referred to it. [70] Conclusion and Orders 1. Mr Vannini has failed to establish that the primary judge erred in rejecting his application for judicial review of the decision of the Panel to revoke the medical assessment certificate issued by the approved medical specialist and to issue a new medical certificate. There is no reason why costs should not follow the event: Uniform Civil Procedure Rules 2005 (NSW), r 42.1. 2. Accordingly, I propose the following orders: 1. Grant leave to appeal; 2. Direct the appellant to file a notice of appeal in the form contained in the White Book within 7 days; 3. Appeal dismissed; 4. Appellant to pay the first respondent's costs. 1. BARRETT AJA: I agree with Gleeson JA. ********** Endnotes 1. Workplace Injury Management and Workers Compensation Act 1998 (NSW) (Management Act), s 314. 2. Vannini v Worldwide Demolitions Pty Ltd [2018] NSWSC 572 (Primary judgment). 3. Supreme Court Act 1970 (NSW), s 101(2)(r). 4. Workers Compensation Act 1987 (NSW) (WC Act), s 151H. 5. Bindah v Carter Holt Harvey Woodproducts Australia Pty Ltd [2014] NSWCA 264 at [109] (Emmett JA, Meagher and Ward JJA agreeing). 6. Campbelltown City Council v Vegan [2004] NSWSC 1129 at [74]-[76] (Wood CJ at CL); Riverina Wines Pty Ltd v Registrar of the Workers Compensation Commission of NSW [2007] NSWCA 149 at [72] (Campbell JA); Pitsonis v Registrar of the Workers Compensation Commission (2008) 73 NSWLR 366; [2008] NSWCA 88 (Pitsonis) at [20] (Mason P). 7. Bunnings Group Ltd v Hicks [2008] NSWSC 874 at [58] (Simpson J). 8. [2008] NSWCA 116 (Siddick). 9. Siddik at [100] (McColl JA, Mason P agreeing). 10. Primary judgment at [59]. 11. Workers Compensation Legislation Amendment Act 2010 (NSW), Sch 2 [14]. 12. Primary judgment at [14]. 13. Primary judgment at [34]. 14. Panel's reasons at [8]. 15. Panel's reasons at [9]. 16. Panel's reasons at [12]-[13]. 17. Panel's reasons at [14]. 18. Panel's reasons at [4]. 19. Panel's reasons at [30]-[37]. 20. Panel's reasons at [40]-[41]. 21. Cole v Wenaline Pty Ltd [2010] NSWSC 78. 22. Vitaz v Westform (NSW) Pty Ltd [2011] NSWCA 254 (Vitaz) at [43]. 23. Panel's reasons at [42]. 24. Primary judgment at [42]. 25. [2018] HCA 34; (2018) 359 ALR 1 (Hossain). 26. Hossain at [24] (Kiefel CJ, Gageler and Keane JJ). 27. Hossain at [25]. 28. Hossain at [27]. 29. Primary judgment at [46]. 30. Primary judgment at [51]. 31. Primary judgment at [52]. 32. (2008) 73 NSWLR 366; [2008] NSWCA 88 (Pitsonis) at [47]-[49] (Mason P, McColl and Bell JJA agreeing). 33. Primary judgment at [56]. 34. Primary judgment at [56]. 35. Primary judgment at [57]. 36. Siddik at [95]-[97], [100]. 37. Primary judgment at [59]. 38. Primary judgment at [60]. 39. (2003) 214 CLR 118; [2003] HCA 22 at [20]-[31]. 40. Primary judgment at [61]. 41. Campbelltown City Council v Vegan (2006) 67 NSWLR 372; [2006] NSWCA 284 (Vegan) at [26] (Handley JA) and [117] (Basten JA). 42. Ibid. 43. Primary judgment at [76]. 44. Primary judgment at [86]. 45. Vegan at [121]-[122] and [128] (Basten JA, Handley and McColl JJA agreeing). 46. AT 2 (5-7). 47. Siddik at [91]-[104] (McColl JA, Mason P agreeing). 48. Versace v Australia's Best Tyres & Auto Pty Ltd [2016] NSWSC 1540 at [39] (Schmidt J); Siddik at [95] (McColl JA, Mason P agreeing). 49. AT 3 (33-39). 50. AT 41 (45-50) – 42 (1-11). 51. At 29 (24-39). 52. [2018] HCA 30; (2018) 92 ALJR 713 at [48]-[49]. 53. SAS Trustee Corporation v Miles [2018] HCA 55; (2018) 92 ALJR 1064 at [20] (Kiefel CJ, Bell and Nettle JJ). 54. Ibid. 55. Mahenthirarasa v State Rail Authority of New South Wales [2008] NSWCA 101; (2008) 6 ADCR 61 (Mahenthirarasa v SRA) at [59] (Basten JA) referring to the comments of Gleeson CJ in Plaintiff S157/2002 v The Commonwealth (2003) 211 CLR 476; [2003] HCA 2 at [13]. 56. Merza v Registrar of the Workers Compensation Commission [2006] NSWSC 939 (Merza) at [35]. 57. Pitsonis at [46]. 58. Ibid at [48] 59. Ibid at [49]. 60. Merza at [39]. 61. Mahenthirarasa v SRA at [60] (Basten JA). 62. Pitsonis at [49]. 63. At [59]. 64. New South Wales Legislative Assembly, Parliamentary Debates (Hansard), 19 June 2001 at 14775. 65. Branir Pty Ltd v Owston Nominees (No 2) Pty Ltd (2001) 117 FCR 424; [2001] FCA 1833 at [24] (Allsop J); Aldi Foods Pty Ltd (ACN 086 210 139) v Moroccanoil Israel Ltd [2018] FCAFC 93 at [45]; (2018) 358 ALR 683 at [45] (Perram J, Allsop CJ and Markovic J agreeing). 66. See by analogy, Minister for Immigration and Border Protection v SZVFW at [48]-[49]. 67. Minister for Immigration and Ethnic Affairs v Wu Shan Liang (1996) 185 CLR 259 at 291; [1996] HCA 6 at [24]. 68. AT 14 (1-12); 16 (14-20). 69. At 291 (Kirby J). 70. Wingfoot Australia Partners Pty Ltd v Kocak (2013) 252 CLR 480; [2013] HCA 43 at [55] (French CJ, Crennan, Bell, Gageler and Keane JJ). 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: 17 December 2018