Gatt v State of New South Wales

The Parties

1. Mr Gatt and State of New South Wales as his employer are the active parties. I will refer to the State as the employer. The Appeal Panel, the Registrar of the Workers Compensation Commission and the Workers Compensation Commission itself are named as defendants for whom the Crown Solicitor has filed submitting appearances. Grounds of review
2. The plaintiff seeks relief on the following grounds: Ground 1: the Appeal Panel fell into jurisdictional error by determining the appeal on grounds which were not those on which the appeal was made. Ground 2: the Appeal Panel fell into jurisdictional error by misconceiving its function by reviewing Dr Weisz's first MAC rather than the second; Ground 3: the Appeal Panel fell into jurisdictional error by misconceiving its function because in substance it found no impairment resulted from the injury. According no occasion arose for making a deduction; Ground 4: the Appeal Panel's decision was legally unreasonable for the reasons explained in ground 3; Ground 5: the plaintiff was denied procedural fairness. The substance of this ground relates to the same matter as grounds 3 and 4; and Ground 6: in the alternative, the Appeal Panel made a non-jurisdictional error of law on the face of the record of the decision. The particulars repeat grounds 1 to 5.

Facts

1. The primary facts underpinning Mr Gatt's claim are not in dispute. The summary which appears below is derived from the material that was placed before the Dr Weisz and the Appeal Panel.
2. Mr Gatt was born in 1957. He is married with four children. He left school in 1975 and was apprenticed to an upholsterer. He left this work after about 2 years and took up employment with the then Public Transport Commission as a bus conductor. He had no injury or disability at the commencement of that employment. He has been an extremely fit and active man who swam, surfed, played tennis and golf and ran right up until the 2011 injury. As many of the medical specialist who have treated him, or assessed him, since this claim arose have remarked he has proved himself a highly motivated worker over many decades in the government service.
3. Mr Gatt first injured his right shoulder when he fell down the stairs on a double decker bus while working as a bus conductor. This injury required shoulder reconstruction surgery from which he made an excellent recovery which left him symptom-free.
4. In or about 1980, the plaintiff commenced working for the NSW Ambulance Service as an ambulance officer. His recruitment involved him undergoing medical examination and fitness testing. He had no difficulty performing the full range of duties required. In 1984 he qualified as an intensive care paramedic. And in 1991 he was selected to train as a member of the Special Casualty/Access Team. This team engages in search and rescue work. The work involves helicopter extractions often in difficult bush terrain or on the water. Again the selection process was rigorous and required him to pass a medical assessment. He was accepted without difficulty.
5. On 1 February 1993, while Mr Gatt was engaged on a helicopter rescue operation in the Blue Mountains, the helicopter crashed at Blackheath. He had released his harness to restrain a colleague who was sitting in the open doorway. He suffered, among other things, an injury to his right shoulder. He had limited time off work, and a period on light duties before returning to full duties. From this time he had ongoing trouble with his shoulder involving pain and a reduction in the range of movement but he continued in his usual work which was at times arduous involving, as I have said, difficult extractions in difficult terrain.
6. On 3 December 2011, the plaintiff suffered a frank injury to his right shoulder. He was again involved in an extraction from Blue Mountains bushland. He and his colleague were lowered into rough bushland terrain to rescue a patient who had fallen and suffered fractures. The patient weighed over 100 kg. It was necessary to move the patient in a rescue basket up a steep track to a clearing on top of a ridge from where he could be winched to a hovering helicopter. While negotiating a fallen tree across the track the basket started to slide back down the track requiring Mr Gatt to exert effort and strain in restraining its downhill movement. He suffered immense pain in his right shoulder, and an umbilical hernia. The latter was ultimately surgically repaired and is not the subject of this claim.
7. Mr Gatt consulted his GP on 8 December 2011. He was referred for an MRI scan and to a shoulder specialist, Dr David Duckworth. The MRI of 13 December 2011 showed glenohumeral joint osteoarthrosis with bone-on-bone articulation. Dr Duckworth diagnosed osteoarthritis of the right shoulder aggravated by the injury. He recommended conservative treatment with anti-inflammatory medication and the gradual resumption of normal activities.
8. Mr Gatt continued with his normal work, reducing some of his sporting activities. He saw Professor David Sonnabend for a second opinion on or about 8 February 2013. He too diagnosed glenohumeral joint osteoarthritis, recording the history of work related injury. He regarded prosthetic shoulder replacement, or arthroplasty, as a future certainty but advised putting it off for as long as possible to reduce the prospect of a second procedure during Mr Gatt's lifetime. He recommended conservative treatment including an exercise program directed at preserving shoulder strength and movement.
9. In about early 2014 Mr Gatt accepted a secondment to the Aeromedical Control Centre as the Operations Officer. He found that the static postures involved in the necessary computer work increased the pain and stiffness in his right shoulder. He re-consulted Dr Duckworth who carried out a total shoulder prosthetic replacement on 9 April 2014. He returned to work initially on light duties on 28 April 2014 on his secondment. He returned to his usual duties as a paramedic on the helicopter in early 2015. He has suffered exacerbations of his shoulder pain from time to time at work.

The claim for permanent loss compensation

1. Mr Gatt made a permanent impairment claim in writing signed by him and dated 21 December 2016 which was served on the first defendant under cover of his solicitor's letter of 23 December 2016. Compensation was claimed for whole person impairment under s 66, and pain and suffering under s 67, Workers Compensation Act 1987 (NSW) ("WCA"). Section 67 is now repealed. The 2011 injury was the only injury relied upon to found the claim.
2. The claim was supported by the medico-legal report of Dr David Millons dated 11 October 2016. Dr Millons referred to each of the three frank injuries I have referred to above. He was of the opinion that Mr Gatt made an excellent recovery from the 1977 injury following the shoulder reconstruction. In his view Mr Gatt's right shoulder subluxed in the helicopter crash on 1 February 1993 and "[s]houlder problems really continued from that time on". Dr Millons regarded the 2011 injury as "a particularly severe aggravation". He commented that it was from that time that shoulder replacement was contemplated. He described Mr Gatt's current condition as involving "a right total shoulder replacement for severe osteoarthritis". He concluded: There is a direct relationship between the condition found on examination and the injuries sustained in the accident/s with particular note being made of the helicopter crash in 1993 and the canyon rescue in 2011. He assessed Mr Gatt's WPI, including a small proportion for surgical scarring, at 22 per cent. He regarded the WPI as due to the helicopter crash in 1993, the 2011 injury and the nature and conditions of Mr Gatt's work with the ambulance service. Dr Millons wrote: Under the circumstances, I would have thought that the impairment relates particularly to things that have happened to him during his time in the ambulance service and [22 per cent WPI] reflects that. No deduction would seem appropriate under the circumstances.
3. The solicitors for the employer acknowledged the claim by letter dated 31 January 2017 and notified Mr Gatt's solicitors of a medical assessment arranged with Dr Roger Pillemer for 27 March 2017. Although received after the inception of the dispute resolution procedures in the Workers' Compensation Commission, it seems convenient to deal with Dr Pillemer's opinion now. In his report of 27 March 2017, Dr Pillemer recorded the history received of the original injury in 1977 and accepted that following surgery then Mr Gatt "had an excellent result with no further problems thereafter". From the history he received, Dr Pillemer regarded Mr Gatt's main concern as commencing with the 1993 helicopter crash, and "he has had ongoing problems since then". Dr Pillemer accepted that Mr Gatt's shoulder subluxated in the 2011 injury and recorded that the MRI showed "at that stage he already had advanced osteo-arthritic change in his shoulder with posterior subluxation of his humeral head". He expressed the following opinion about "attributability": In my opinion the majority of Mr Gatt's ongoing problems are related to his injury of 1 February 1993 when the helicopter crashed, noting that by the time of his injury in December 2011 he already had advanced degenerative changes present. From a medical point of view he regarded Mr Gatt's work as an intensive care paramedic "in any shape or form" as contra-indicated by reason of the risk of damage to the underlying total shoulder replacement due to the heavy nature of the work involved.
4. Dr Pillemer assessed Mr Gatt's whole person impairment as 20 per cent and did not make an allowance for the surgical scarring. In his opinion, the 2011 injury "was simply an aggravation of an advanced underlying osteo-arthritic condition of [Mr Gatt's] right shoulder which had been symptomatic since February 1993". Without the 2011 injury, he still "would have eventually required total shoulder replacement … slightly later than occurred in April 2014". He regarded one-fifth of the impairment as due to the aggravation by the 2011 injury "with the remainder being due to his earlier injuries, particularly on 1 February 1993".

Medical assessment proceedings

1. On 27 February 2017, Mr Gatt lodged an application to resolve a dispute concerning his claim for lump sum compensation with the Workers Compensation Commission. Extensive medical evidence and a detailed statement from Mr Gatt were attached to the application in accordance with the usual practice. The employer's reply, dated 13 March 2017, attached reports of Dr Longhurst and Professor Sonnabend and stated the employer was unable to determine liability as it was awaiting Dr Pillemer's assessment. An application to admit Dr Pillimer's report late was made on 28 March 2017. This application was acceded to.
2. On 4 April 2017, an amended request for assessment of Mr Gatt's permanent impairment was forwarded to Dr Weisz, as approved medical specialist by the delegate of the Registrar. The medical dispute referred for assessment was described in the referral as extending to: The degree of permanent impairment of the worker as a result a result of an injury (319(c)); Whether any proportion of permanent impairment is due to any previous injury or pre-existing condition or abnormality, and the extent of that proportion (s 319(d); Whether impairment is permanent (s 319(f)); Whether the degree of permanent impairment of the injured worker is fully ascertainable (s 319(g)).
3. Dr Weisz examined Mr Gatt on 21 April 2017 and issued his medical assessment certificate, including his reasons (as required by s 325(2)(c)) on 27 April 2017 in accordance with s 325 WIM Act. Dr Weisz assessed the WPI of Mr Gatt at 21 per cent, including 1 per cent for the scarring and deducted three-quarters of the impairment referrable to the right arm (75%) under s 323 WIM Act. Leaving a combined total of 6 per cent. He expressed his reasons at para. 10(a) of the certificate in the following terms: The condition is a result of subsequent (to 1977 injury) accidents between 1993 and 2001, as well as the heavy duties that he performed along the years as an ambulance medic. I consider the last event in 2011 as a deemed date for all the accidents as it would be illogical and not scientific to consider it an unrelated event. The assessment on the day of examination is based on joint replacement and on reduced range of movements of the right shoulder. The accident of 2011, if taken separately, would be a quarter of the assessed impairment. (My emphasis and interpolation.) It's evident that he treated the consequences of the accidents he identified as a single injury because (at para.11) he said there were no relevant previous injuries, pre-existing conditions or abnormalities. Dr Weisz also stated "there is no deductible proportion" under s 323 WIM Act but indicated a 75% s 323 deduction in table 2 to the MAC.
4. Neither side was content with Dr Weisz's first MAC. Mr Gatt's solicitor contended that the MAC contained an obvious error because Dr Weisz had made the 75 deduction for a pre-existing injury, condition or abnormality when his reasons stated he had found none. The solicitors wrote to the Registrar on 1 May 2017 asking that either the Registrar correct the error and issue a replacement MAC, or approve of Dr Weisz issuing the replacement certificate in accordance with s 325(3) WIM Act. On 8 May 2017, the employer's solicitors wrote to the Registrar indicating what they regarded as demonstrable errors in the medical certificate which was elaborated in various ways, but basically boils down to the criticism that Dr Weisz appeared to overlook that what had been referred for assessment was a whole person impairment resulting from a frank injury of 3 December 2011, and associated questions. Instead Dr Weisz appeared, in the solicitors' submission, to have treated the impairment to be assessed as one resulting from both the 1993 and 2011 injuries and the nature and conditions of employment in the interval between them. It was pointed out that Mr Gatt had not relied upon a disease injury under WCA. Moreover, Dr Weisz appeared to have overlooked, according to the solicitors, the 1977 accident and that whole person impairment could not ground an entitlement to permanent loss compensation assessed on the basis of WPI for any injury prior to 1 January 2002. The employer consented to the matter being re-referred to Dr Weisz "to rectify the position by assessing what was referred in the first place". The Registrar's delegate re-referred the matter to Dr Weisz on 23 May 2017.
5. Dr Weisz gave the requested replacement (referred to as "Amended" in the documentation) MAC on 2 June 2017. His assessment of 21 per cent WPI was unchanged, but he removed the reference to a 75 per cent deduction for pre-existing injury, condition or abnormality from Table 2. Moreover, he rewrote paragraph 10(a) (see [21] above) so it read: The condition is a result of subsequent (to 1977) severe accidents between 1993 and 2011, as well as the heavy duties that he performed along the years as an ambulance medic. The assessment on the day of my examination is based on joint replacement and on reduced range of movements of the right shoulder. In making that assessment I have taken account of the following matters: A reduced mobility, the scarring, the muscular wastage and review of x-rays (My interpolation). It is evident that Dr Weisz amended his reasons by removing the second and fourth sentences of para 10(a) as set out above at [21]. This removed the reference to a "deemed date" of injury, the reference to the dictates of logic and science and the separate assessment for the 2011 injury as a quarter of the total.

The medical appeal

1. The employer lodged an application to appeal against Dr Weisz's decision on 19 June 2017 under s 327 WIM Act. It relied on the grounds that the assessment was made on the basis of incorrect criteria, and contained a demonstrable error mentioned in s 327(3)(c) and (d). Its written submissions attached its earlier letter of 8 May 2017. I interpolate this may not have been entirely apposite given the changes in Dr Weisz's replacement MAC. The substance of the ground was provided by arguments that the MAC was not given "as to the matters referred for assessment". Only the WPI resulting from the 2011 frank injury had been referred. The employer reiterated its complaint that "a deemed date of injury", incorporating nature and conditions of employment from 1993 to 2011, had not been referred for assessment. This argument was advanced notwithstanding Dr Weisz's deletion of any reference to any deemed date of injury from his reasons. The employer argued that by assessing the WPI resulting from all injuries suffered while working for the employer, Dr Weisz had departed from the specific scope of the referral and misapplied s 323 because he ignored the 1977 injury and failed to make a deduction for the 1993 injury and the nature and conditions of employment between 1993 and 2011. Mr Gatt points out that it was not argued that the glenohumeral osteoarthritis demonstrated on the 2011 MRI scan was itself a pre-existing condition or abnormality within the meaning of s 323(1).
2. Mr Gatt opposed the appeal proceeding in accordance with s 327(4) arguing that none of the grounds for appeal relied upon by the employer had been made out, even "in the face of the application" (s 327(4)). It was accepted that Dr Weisz made reference to Mr Gatt's condition being the result of a number of injuries that occurred while employed by the ambulance service. It was pointed out that Dr Weisz (and Dr Millons and Dr Pillemer), excluded the 1977 injury because surgery then had been successful. It was argued that Dr Weisz's assessment, like Dr Millons's was "based on the 2014 surgery that followed the 2011 injury". It was accepted that the 1993 injury and any injury arising from the nature and conditions of Mr Gatt's employment as an intensive care paramedic thereafter had not been referred for assessment. The argument was repeated that what was assessed were the consequences of the 2014 surgery which had been "necessitated" by the 2011 injury. It was also argued (erroneously having regard to Dr Pillemer's opinion) that there was no medical evidence suggesting that Mr Gatt would have undergone the 2014 surgery had it not been for the 2011 injury.
3. Mr Gatt pointed out that there was no medical evidence which predated the 2011 injury. Accordingly, so it was argued, any deduction under s 323 WIM Act would have been speculative, see Cole v Wenaline Pty Ltd [2010] NSWSC 78 at [29] - [31], Schmidt J.
4. In the alternative, it was submitted that if a deduction under s 323 was appropriate, the deduction should not exceed the statutory assumption of 10 per cent of the impairment assessed in cases where the extent of the required deduction would otherwise be difficult or costly to determine: s 232(2).
5. The employer joined issue with Mr Gatt and argued that the amendments of Dr Weisz's reasons compounded the problem. It was argued, "it is inherently inconsistent to conclude that there is no deductible proportion under s 232 and to indicate in the same opinion, that the condition/impairment relates to heavy work performed as a result of the nature and conditions of employment between 1993 and 2011, and yet then say the entirety of the impairment related to the specific injury in 2011".
6. By decision in writing on 1 August 2007, the Registrar's delegate expressed satisfaction that the replacement medical assessment certificate on the face of the application and the submissions made by the employer made out the ground that there was a demonstrable error in relation to Dr Weisz's consideration of s 323 of WIM Act. The Appeal Panel convened in accordance with s 328(1) WIM Act was constituted by an arbitrator and two approved medical specialists, the first was an orthopaedic surgeon and the second an occupational physician.

The Appeal Panel's decision

1. The Appeal Panel gave its decision on 28 September 2017 deciding to revoke (presumably the replacement) Medical Assessment Certificate of Dr Weisz and issue a new Medical Assessment Certificate. Mr Gatt's whole person impairment referable to his right arm was assessed at 20 per cent together with an additional 1 per cent for scarring. A deduction of three-quarters was made under s 323 and the quotient of 5.25 per cent was rounded down to 5 per cent.
2. In accordance with the statutory guidelines, the Appeal Panel had conducted a preliminary view of the matter and decided it was unnecessary to re-examine Mr Gatt or to convene an appeal assessment hearing. The decision of the Appeal Panel therefore proceeded as a review on the papers that had been before Dr Weisz, the first and superseded MAC of Dr Weisz, the replacement MAC of Dr Weisz and the additional written submissions of the parties on appeal.
3. No complaint about the adoption of this procedure is made before me except as I will detail regarding the reference to Dr Weisz's first MAC which forms part of the argument in relation to some of the grounds of appeal given that it was legally superseded by the replacement MAC.
4. I record in passing that (at Reasons [15]) the Appeal Panel expressed the view that Dr Weisz apparently overlooked the amended referral that included the employer's late document. With respect this is not correct. Dr Pillemer's "detailed report dated March 2017", which Dr Weisz considered accurate and similar to his views, is referred to at page 5, paragraph 10(c) of Dr Weisz's first MAC.
5. The Appeal Panel summarised documentary evidence provided by the parties (Reasons [19] to [35]). No complaint was made about the accuracy of the summary. Mr Gatt's written statement was not summarised, but it was not inconsistent with the histories recorded by the various doctors whose reports were, and no complaint was made about that.
6. The Appeal Panel summarised both of Dr Weisz's MACs. Of the first the appeal panel recorded (at Reasons [36]): This MAC is not the subject of the appeal, but (sic) this has no standing given that it has been superseded by the amended MAC. Dr Weisz's paragraph 10(a) in his first MAC was quoted in full at [40] of the panel's reasons. At Reasons [41], the Appeal Panel recorded its impression that the replacement, or amended, MAC was "in identical terms to the initial MAC" differing only as to paragraph 10 and the omission of the deduction in table 2 on page 6. Dr Weisz "new" paragraph 10(a) was purportedly set out at [45] of the Appeal Panel decision. The quote, however, was not rendered faithfully because it included the deleted fourth sentence: "the accident of 2011, if taken separately, would be a quarter of the assessed impairment". Mr Gatt says the erroneous inclusion of the deleted fourth sentence is indicative of error. The employer argues it is no more than a typographical error.
7. The Appeal Panel summarised the parties submissions (Reasons [48]-[61]) recording (at Reasons [47]) the parties agreement to the determination of the appeal without an assessment hearing.
8. The Appeal Panel's critical findings and reasoning process are set out at Reasons [62] to [98]. This section of their reasons commences with a discussion of the nature of the powers of the Appeal Panel (Reasons [62] - [69). The Appeal Panel referred to s 327(3) and 328 of the WIM Act. Section 327(2) provides that the matter is appealable if it is a matter conclusively presumed to be correct in proceedings before a court or the Workers' Compensation Commission under s 326 WIM Act. The matters referred to Dr Weisz including the degree of permanent impairment and whether a proportion of it is due to any previous injury or pre-existing condition were all matters conclusively presumed to be correct under s 326. Section 328(2) provides 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. The Appeal Panel's statement of its understanding of these matters, with respect was not entirely correct. At Reasons [66] the panel said: In this matter the delegate of the Registrar has determined that he is satisfied that at least one of the grounds of appeal under s 327(3)(d) is made out. The panel has accordingly conducted a review of the material before it and reached its own conclusion concerning the correct assessment of the impairments suffered by the respondent. With respect, the Appeal Panel stated its powers too broadly. In Ingham's Enterprises Pty Ltd v Lakovska [2014] NSWCA 194 at [40], Barrett AJA (Gleeson JA agreeing) said: Under s 328(2), a medical Appeal Panel's function is to make a "review of the original medical assessment", being, however, a review that is "limited to the grounds of appeal on which the appeal is made" being grounds formulated and advanced by the party concerned within the limits allowed by s 327(1). Inghams notes that the part of s 328(2) confining a review to the grounds advanced by the appealing party was added by the Workers Compensation Legislation Amendment Act 2010 (NSW) in apparent response to the decision of this Court in Siddik v WorkCover Authority of New South Wales [2008] NSWCA 116. (See also New South Wales Police Force v Registrar of the Workers' Compensation Commission of New South Wales [2013] NSWSC 1792, Davies J at [45] - [46], [52]; Cullen v Woodbrae Holdings Pty Ltd [2015] NSW SC 1416, Beech-Jones J at [29] - [38]; Ferguson v State of New South Wales & Ors. [2107] NSWSC 887, Campbell J at [12].)
9. It follows that the effect of the 2010 amendment is to limit the breadth of the Appeal Panel's powers as identified by the Court of Appeal in Siddik. It must be taken that Siddik no longer governs the nature of the powers of review conferred on the Appeal Panel by s 328 WIM Act or their exercise.
10. However, notwithstanding, this misstatement of the nature of its powers, it is evident, as will become clear, the Appeal Panel reviewed Dr Weisz's replacement MAC for itself by reference to the grounds advanced by the employer and made its own decision about error in the light of them, at least purportedly so.
11. In deference to the grounds of review advanced by Mr Gatt it is necessary to record that the Appeal Panel referred to s 322 WIM Act concerning, inter alia, "the question of aggregation" (Reasons [68]). It is important to bear in mind in relation to the Appeal Panel's ultimate finding of error that the Panel emphasised that Mr Gatt's application for resolution of a dispute relied upon the 2011 injury and not "any prior injuries or the nature and conditions of employment from 1993 to 2011" (reasons [70]). And, that the terms of the referral to Dr Weisz called for "an assessment of whole person impairment arising from the frank injury sustained by [Mr Gatt] on 3 December 2011" (reasons [71]). Reference was made to s 325(1) WIM Act requiring an approved medical specialist to give a certificate "as to the matters referred for assessment" and to the decision of Malpass AsJ in Aircons Pty Ltd v Registrar of the Workers' Compensation Commission of New South Wales [2006] NSWSC 322 at [20] where his Honour found demonstrable error because the AMS "has addressed matters other than those referred to him for assessment".
12. The Appeal Panel also referred to paragraph 1.6 of the SIRA NSW Workers' Compensation Guidelines for the Evaluation of Permanent Impairment (the guidelines), subparagraph (c) of which is includes the following: In calculating the final level of impairment the assessor needs to clarify the degree of impairment that results from the compensable injury/condition. Any deductions for pre-existing injury/conditions are to be clearly identified in the report and calculated.
13. The appeal panel found error on the grounds advanced by the employer in the following terms (at Reasons [75] - [78]): [75] In this mater, it is apparent from the referral that the AMS was required to assess the whole person impairment of the respondent's right upper extremity and scarring (TEMSKI) due to the injury sustained on 3 December 2011 as identified in Parts 4 and 5.6 of the Application (to resolve a dispute). The AMS did this in his initial MAC, but this was superseded by his Amended MAC. [76] Although Ms Indari submits that the AMS did not refer to a "deemed date" in Table 2 of the Amended MAC, it is clear from paragraph 10a of the Amended MAC that his assessment related to "severe accidents between 1993 and 2011, as well as the heavy duties that he performed along the years as an ambulance medic", rather than just the effects of the frank injury on 3 December 2011. [77] In the Panel's view, the AMS took it upon himself to assess the whole person impairment arising from the nature and conditions of employment, including the injury on 3 December 2011, with a deemed date of injury of 3 December 2011, when he was not requested to do so by the delegate of the Registrar. He also dealt with aggregation and causation issues which were not his concern. He disregarded the referral orders, rather than seek further clarification from the Registrar. In the Panel's opinion, he failed to comply with paragraph 1.6(c) of the Guidelines. [78] In the circumstances and in accordance with s 327(c) of the 1998 Act and the principles set out in Aircons, the Panel is satisfied that the Amended MAC contains a demonstrable error and it should be revoked. The reference to s 327(c) is obviously to be taken as s 327(3)(d). I highlight now the reference in the first paragraph, third line of [77] to "a deemed date of injury of 3 December 2011" and the statement that aggregation and causation issues were "not his concern". These matters form part of Mr Gatt's grounds for judicial review.
14. Moreover, it may be that the decision to revoke the replacement MAC upon demonstration of demonstrable error is inapt. The Appeal Panel's powers are powers of review subject to the limitation in s 328(2). Revocation of an MAC does not necessarily follow the demonstration of error. In most cases, if not always, revocation of an MAC will only follow when the Appeal Panel in the exercise of its powers of review, having found error comes to a different conclusion from that reached by the AMS. This inaptness may be illustrated by the consideration that during their review the Appeal Panel identified a further error at [89] of its decision, reproduced at [46] below.
15. In any event, the Appeal Panel went on to consider the matters referred to Dr Weisz for themselves. The Panel agreed with Dr Weisz's findings and calculations, saying they had "no reason to cavil with the doctor's calculations" (Reasons [80]). The Panel expressed its satisfaction that Mr Gatt's degree of permanent impairment is 20 per cent whole person impairment referrable to the injury to the upper extremity and 1 per cent for scarring producing a total of 21 per cent WPI. The members of the Appeal Panel then turned their mind to the application of s 323 of the Act. It is apposite to set out s 323 WIM Act in full here: (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 (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1987 Act) or that is due to any pre-existing condition or abnormality. (2) If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the available evidence. Note. So if the degree of permanent impairment is assessed as 30% and subsection (2) operates to require a 10% reduction in that impairment to be assumed, the degree of permanent impairment is reduced from 30% to 27% (a reduction of 10%). (3) The reference in subsection (2) to medical evidence is a reference to medical evidence accepted or preferred by the approved medical specialist in connection with the medical assessment of the matter. (4) The Workers Compensation Guidelines may make provision for or with respect to the determination of the deduction required by this section. (5) (Repealed) Note. Section 68B of the 1987 Act makes provision for how this section applies for the purpose of calculating workers compensation lump sum benefits for permanent impairment and associated pain and suffering in cases to which section 15, 16, 17 or 22 of the 1987 Act applies.
16. The Appeal Panel referred to decisions of this Court, by the Court of Appeal and at first instance, concerning the meaning and application of s 323 and its predecessor s 68A WCA. It is unnecessary to list these authorities. It was not argued they were wrongly stated, inapposite, or misapplied.
17. Contrary to Dr Weisz's replacement MAC, the Appeal Panel decided that s 323 was engaged and that Mr Gatt's whole person impairment should be reduced by the proportion of three-quarters Dr Weisz had originally assessed, as I have stated at [30] above. The Appeal Panel's reasoning about this needs to be considered in full (Reasons [89] - [97]). [89] The Panel is of the view that the AMS was in error for failing to make a deduction for the pre-existing pathology. The size of the deduction needs to take into account the evidence of quite extensive pre-existing degenerative changes, on a background of prior symptoms. [90] The Panel disagrees with Ms Indari's submission that there was no evidence that would allow for an assessment to be made on any basis other than by an assumption or hypothesis in accordance with the principles in Cole. [91] According to the history recorded by Dr Millons, the respondent experienced problems with his right shoulder over the years after the 1993 incident, but he continued to work and put up with his on-going problems. Although the doctor referred to the respondent suffering a significant injury in 2011, he was able to work on with his symptoms until he eventually had surgery in 2014. [92] Similarly, Dr Pillemer noted that the respondent had on-going problems with his shoulder since the helicopter crash in 1993. The doctor recorded that after the respondent's shoulder dislocated on 3 December 2011, he was able to complete the shift and continued to work. Therefore, it is apparent from these reports that the respondent was not symptom-free prior to the incident in 2011. [93] Whilst it is true that the respondent had an MRI scan after the 2011 incident, this test showed profound and advanced degenerative changes. These changes would not have been caused by the incident 10 days earlier and the surgery in 2014 was undertaken to address the longstanding degenerative changes in the shoulder. [94] There is no evidence to support the respondent's submission that the need for surgery in 2014 arose as a consequence of the injury in 2011 and there is no evidence to suggest that the respondent would have undergone the surgery had it not been for the 2011 injury (sic). [95] In the Panel's view, the incident in 2011 does not appear to have been major, given that the respondent performed his usual duties for a further three years and it does not appear to have been the pivotal incident giving rise to the need for surgery in 2014. Were it not for the presence of the degenerative changes, the incident in 2011 would not have been sufficient to give rise to the need for surgery. [96] The Panel does not agree that there is a lack of evidence relating to the previous injuries to justify a deduction of only one tenth. It is clear that the respondent had longstanding degenerative changes on a background of a number of prior injuries. Whilst Dr Pillemer suggested a deduction in the order of four fifths, the Panel considers that a deduction of three quarters of the entire whole person impairment, as suggested by the AMS in his initial MAC, is appropriate in the circumstances. [97] For these reasons, the Panel has therefore determined that the Amended Medical Assessment Certificate dated 2 June 2017 should be revoked, and a new Medical Assessment Certificate should be issued. The new Medical Assessment Certificate is attached to this statement of reasons.
18. The Appeal Panel's new MAC certified that Mr Gatt suffered a 5 per cent whole person impairment as a result of the 2011 injury, under the s 66(1) WCA threshold for an entitlement for permanent loss compensation.

Ground 1

1. In her written submissions, Ms M Allars SC (PWS [2.3]) explained that the substance of Ground 1 is that the Appeal Panel exceeded the limitation upon its powers imposed by s 328(2) by deciding the appeal on a ground which was not one of the grounds of appeal on which the appeal was made by the employer.
2. Learned Senior Counsel argues that it is necessary to understand the context in which the replacement MAC of Dr Weisz, the MAC under appeal, was made. These circumstances are fully discussed and set out above. I will not repeat them here. However, Ms Allars argues, with some force, that although the Registrar's delegate had "approved of", in the statutory language, Dr Weisz correcting the "obvious error", the former did not identify that error but, in all probability, simply provided the competing letters of submission for Mr Gatt and the employer who both agreed, for very different reasons, that the MAC was affected by obvious error. The inference is, so it is submitted, that Dr Weisz proceeded on the basis that the obvious error consisted of the s 323 deduction he had allowed on his table of calculation of Mr Gatt's WPI.
3. I interpolate that my own impression is that Dr Weisz did two things. First he deleted all reference to any deemed date of injury, logic or science which addressed some of the complaints made by the employer, as I have discussed. Secondly, he removed the deduction which addressed the complaint made by Mr Gatt.
4. The Medical Panel's conclusion that grounds of appeal within s 327(3) have been made out is found at [77] of its decision (see also Reasons [89]), which I have set out above. Ms Allars impugns this conclusion at a number of different levels which in summary are (not in the order in which they were advanced): 1. The Appeal Panel wrongly concluded that in his replacement MAC Dr Weisz had assessed the whole person impairment resulting from all of the 1993 injury, the nature and conditions of employment in the interval and the 2011 injury. It was argued that the Appeal Panel's reference to the "deemed date of injury of 3 December 2011" (Reasons [77]), which did not appear in the replacement MAC demonstrated that the Appeal Panel confused the original MAC with the replacement MAC. 2. The Appeal Panel was wrong to say that questions of aggregation and causation referred to by Dr Weisz "were not his concern". The Appeal Panel was in error when it held that guideline 1.6(c) had not been complied with. And this was not a ground identified in the employer's application to appeal and could not stand in any event as in the replacement MAC Dr Weisz had found that there was no pre-existing condition and therefore no deduction to be made; 3. It was an error in the course of its review for the Appeal Panel to make a deduction in respect of a pre-existing condition of osteoarthritis when such a ground had never been advanced by the employer. Rather the employer had complained about Dr Weisz taking the previous injuries into account. Deciding that a deduction was called for by reason of "pre-existing" osteoarthritis denied Mr Gatt procedural fairness because he was not aware that such a decision could be made because it was not one of the employer's grounds.
5. Ms K C Morgan SC, who appeared with Ms M Jaireth for the employer, joined issue with these submissions. First, they submit that the question of pre-existing degenerative osteoarthritis was an issue before the Appeal Panel raised fairly by the employer's submissions. Secondly, non-compliance with paragraph 1.6(c) was fairly before the Appeal Panel even if it was not specifically mentioned in the employer's submissions. The ground referred to in s 327(3)(c) WIM Act, the "incorrect criteria" ground, was propounded by the employer and the substance of its argument was the failure of Dr Weisz to specify a s 323 WIM Act deduction in the replacement MAC. Thirdly, the Appeal Panel's reference to a "deemed date of injury" did not result from either confusion as to which MAC was in question nor overzealousness on the part of the Appeal Panel in the sense of scrutinising the replacement MAC too closely for the detection of error. It was pointed out that at Reasons [36] the Appeal Panel emphasised that Dr Weisz's first MAC was not the subject of the Appeal, it had no standing, and had been superseded. It was open to the Appeal Panel to infer that despite the withdrawal of sentences 2 and 4 in paragraph 10(a) of the first MAC, the substance of Dr Weisz's reasons indicated he remained of the view he had expressed in the first MAC. Fourthly, in relation to the conclusion expressed at Reasons [77], the Appeal Panel was not criticising Dr Weisz for making necessary findings about causation. Rather, the emphasis of the Appeal Panel was on the failure of Dr Weisz to follow the analysis of Schmidt J in Elcheikh v Diamond Formwork (NSW) Pty Ltd in Liquidation [2013] NSWSC 365 at [126] - [127]. Other than for the scarring, no question of aggregation arose. If the Appeal Panel was wrong, its error was not material.

Consideration of ground 1

1. Ms Allars is correct in submitting that the Appeal Panel detected demonstrable error in Dr Weisz's replacement MAC because he failed to make a deduction from Mr Gatt's whole person impairment in respect of a pre-existing degenerative condition of osteoarthritis. The Appeal Panel's conclusion as to error, as I have sought to demonstrate above, was principally succinctly stated at Reasons [77] - [78]. The demonstrable error recorded in that passage was the failure to comply with s 325(1), that is to say, a failure to give a certificate as to the matters referred for assessment. That error was fleshed out in the Appeal Panel's reasons at Reasons [73] by reference to the decision of Malpass AsJ in Aircons. In the Appeal Panel's view, Dr Weisz, in the language of Malpas AsJ (at [21], Aircons) had addressed matters other than those referred to him for assessment because at replacement MAC para. 10(a), the amendments notwithstanding, Dr Weisz continued to approach the task of assessment by reference to a "condition [that] is a result of subsequent [to the 1977 injury] severe accidents between 1993 and 2001, as well as the heavy duties that he performed along the years as an ambulance medic". This matter was in the vanguard of the employer's complaints from the outset. It insisted that the task referred to Dr Weisz by the Registrar's delegate was to assess Mr Gatt's whole person impairment as a result of the 2011 injury only. For this purpose, the 1993 injury, the nature and conditions of the employment and for that matter, on the employer's argument, the 1977 injury, were previous injuries for the purpose of s 323 (1) of the Act.
2. Later in their decision the Appeal Panel (at Reasons [89]), albeit it logically while reviewing the material for themselves, expressly found error on the part of Dr Weisz in failing to make a s 323 deduction for pre-existing pathology, which I take to be a reference to the osteoarthritic changes shown on the December 2011 MRI scan. The Appeal Panel described this pathology as "quite extensive pre-existing degenerative changes". Ms Allars argument is that the employer's complaint was about "previous injuries" not a "pre-existing condition" within s 323 WIM Act.
3. It is true that the employer did not refer in express terms to any pre-existing condition or abnormality separate from the previous injuries. In substance the employer's complaint was that the referral required Dr Weisz to assess Mr Gatt's whole person impairment resulting from the 2011 injury and to deduct therefrom the proportion of the impairment due to the previous injuries.
4. The material before the Appeal Panel, so far as it addressed these issues, was all one way, including the report of Dr Pillemer obtained by the employer. There was simply no dispute about Mr Gatt's condition. It was the result of a series of traumatic injuries suffered in the course of his employment with the employer commencing with the 1993 helicopter crash injury, involving the ongoing infliction of traumata in the nature and conditions of his heavy work ultimately concluding with the 2011 injury after which he came under medical investigation and treatment culminating in the performance of the prosthetic total shoulder replacement on 9 April 2014. As I have said, all of the medical evidence and Mr Gatt's statement were to this effect. It is also indisputable that as a consequence of this series of injuries, Mr Gatt had developed severe osteoarthritis in his right shoulder as described in my review of the medical material above (see eg [16]-[18]). It was that condition that necessitated the surgery of 9 April 2014 which involved the excision of the arthritic joint and its replacement with prosthetics to relieve the debilitating symptoms Mr Gatt had been increasingly experiencing. None of this was in issue between the parties. Nor was it in issue between the parties, or in the minds of the members of the Appeal Panel, that Mr Gatt's whole person impairment resulting from this series of injuries was in the order of 21 per cent, when one added the 1 per cent due to the surgical scarring.
5. What was in issue between the parties was the significance, for the purpose of assessing Mr Gatt's whole person impairment, of the injuries prior to the 2011 injury. Mr Gatt's approach was to say, effectively, that the 2011 injury was the sole cause of his whole person impairment because it was the last significant injury; it brought him to medical investigation and ongoing treatment culminating in the surgery; and it was the surgery, which is to say the prosthetic shoulder replacement, and the reduced range of shoulder movements as a consequence of the surgery, that accounted for the whole of the assessed permanent impairment. No s 323 deduction was called for, on this argument.
6. The employer's argument was very different. Its case included an argument that, notwithstanding the overwhelming contrary medical opinion, one could not discount the 1977 injury as a cause of Mr Gatt's WPI. In any event the 1993 injury and the intervening nature and conditions of employment trauma up until the 2011 injury, as I have said, were previous injuries within s 323 WIM Act. Part of that argument was as Mr Gatt had relied solely upon the 2011 injury as a single frank injury, it was inescapable that the other matters to which I have referred, were previous injuries. Moreover, they had clearly contributed to the underlying pathology which was the clinical entity which the surgery addressed. If this was so, then a proportion of the whole person impairment following the surgery must be due to those prior injuries and a deduction needed to be made.
7. The view that the clinical entity requiring surgery resulted from all of the injuries received by Mr Gatt in the course of his employment with the employer was consistent with Dr Pillemer's views upon which the employer relied and those of Dr Millons, upon which Mr Gatt relied. In truth there was no contrary view in the medical material put before Dr Weisz and then the Appeal Panel by the parties.
8. In my judgment the Appeal Panel set about the performance of its legislative task in a two-step approach. First, it sought to identify whether any of the grounds on which the appeal was made had been made good. As I have said, it concluded in the employer's favour, as I have said, that Dr Weisz had erred (at Reasons [77] - [78]). Then in the second stage, it turned to review the question of whole person impairment including whether as part of that process a deduction was required under s 323(1) WIM Act. During the review the Appeal Panel identified the additional, indeed, in their view, critical error (at Reasons [89]).
9. In my judgment in the first stage the Appeal Panel identified two discrete errors. The first was the Aircons error. And, the second was dealing "with aggregation and causation issues which were not his concern". The finding as to the first error was expressed in this way, which I will repeat, (at Reasons [77] - [78]). In the Panel's view, the AMS took it upon himself to assess the whole person impairment arising from the nature and conditions of employment, including the injury on 3 December 2011, with a deemed date of injury of 3 December 2011, when he was not requested to do so by the delegate of the Registrar … he disregarded the referral orders, rather than seeking further clarification from the Registrar. In the Panel's opinion he failed to comply with paragraph 1.6(c) of the guidelines. In the circumstances, and in accordance with s 327(3) of the 1998 Act and the principles set out in Aircons, the Panel is satisfied that the [replacement] MAC contains a demonstrable error and it should be revoked. It can be seen that this passage squarely regards Dr Weisz's approach as going beyond "the matters referred for assessment" in that "he has addressed matters other than those referred to him for assessment": see Aircons at [20] - [21]. And it seems tolerably clear that this error is characterised as both applying "incorrect criteria" (327(3)(c) WIM Act) and as "a demonstrable error" (s 327(3)(d) WIM Act). Both characterisations relate to the failure to comply with paragraph 1.6 (c) of the guidelines, relevantly extracted at [41] above.
10. There are some syntactical errors in the passage from the Appeal Panel's reasons. For instance, as written (at [78]) "s 327(c)" is referred to rather than s 327(3)(d) when referring to demonstrable error. Given the identification of the Aircons error, the failure to comply with paragraph 1.6(c) of the guidelines can be understood as a failure to clarify the degree of permanent impairment that results from the 2011 injury, being the only injury referred to in the delegate's written referral, and a failure to "clearly identify any deductions for pre-existing injuries/conditions" (Reasons [74]; 1.6(c) guidelines).
11. With respect, I do not agree that the reference to "deemed date of injury of 13 December 2011" (Reasons [77]) represents confusion or overzealousness. At Reasons [40] the Appeal Panel had set out paragraph 10 from Dr Weisz's original MAC and his view that the 2011 injury should be taken "as a deemed date for all the accidents". At Reasons [41] the Appeal Panel made clear that the replacement MAC differed so far as paragraph 10 was concerned and that version was set out at Reasons [45]. This quote contained an error in as much as the fourth sentence from the first MAC was erroneously reproduced: "[t]he accident of 20011, if taken separately, would be one-quarter of the assessed impairment". This fourth sentence does not appear in the replacement MAC, but that error of composition was not repeated, and so far as I can see, was not relied upon in the balance of the reasons. I interpolate, it appears to have had no effect on the Appeal Panel's decision.
12. The Appeal Panel recorded the submission made on behalf of Mr Gatt (at Reasons [76]) that the replacement MAC did not refer to a deemed date of injury. The Appeal Panel accepted that was so but emphasised that Dr Weisz's replacement assessment related to all the incidents in Mr Gatt's employment with the employer "rather than just the effects of the frank injury on 3 December 2011". The reference to "deemed date of injury" in Reasons [77] should be understood as the Appeal Panel's evaluation that while Dr Weisz had changed his report by omitting sentences 2 and 4 from paragraph 10(a), in substance, he had not changed his views. He was still approaching the assessment on the basis that Mr Gatt's whole person impairment should be assessed by reference to all of the injuries, and injurious circumstances, suffered in the course of his employment with the employer. It may possibly have been discourteous to Dr Weisz to have expressed themselves as they did, but the Appeal Panel's conclusion that, in substance, Dr Weisz had not changed his views was well and truly open to them. Frankly, it is not necessarily critical of Dr Weisz. I do not regard the interpolation "deemed date of injury", in context, as indicative of error on the Appeal Panel's part.
13. I am also of the view that the reference to Clause 1 of paragraph 1.6(c) of the guidelines was permissible even having regard to the constraints imposed by s 328(2) WIM Act. The employer may not have invoked that paragraph expressly in its submissions. Paragraph 7 of the employer's written submissions identified the error contended for by the employer as a failure by Dr Weisz to assess in accordance to the Registrar's referral and the provisions of the Act. It was put that Dr Weisz needed to assess the percentage whole person impairment resulting from the 2011 frank injury, deducting the percentage whole person impairment arising from any "pre-existing injury/condition" under s 323 WIM Act. This does not precisely describe the required legal process as the Appeal Panel's reference to applicable authority makes clear. But it does demonstrate substantive engagement with paragraph 1.6(c) and the need to make clear the steps followed in arriving at the, final, assessment. Even if the Appeal Panel fell into error by referring to 1.6(c) the error was not material to their decision because of their finding of Aircons error and the error identified at Reasons [89].
14. I accept that the Appeal Panel erred when they ruled that issues of aggregation and causation were not matters properly within the purview of Dr Weisz. I understand questions of aggregation to be a reference to the requirement that impairments resulting from the same injury are to be assessed together as part of the one assessment of the degree of permanent impairment of the injured worker resulting from an injury. Where more than one injury, in the sense of injurious consequences, arises out of the same incident any resulting impairments are to be likewise to be assessed together producing a single, total degree of permanent impairment. These matters are dealt with in s 322(2) and (3) and are an integral part of the medical assessment process established by Part 7 of Chapter 7 WIM Act.
15. Questions of causation necessarily arise when assessing the degree of permanent impairment of a worker as a result of an injury: s 319(c). The phrase - "as a result of" - permeates the whole of the WIM Act and the WCA and, if I may put it this way, represents the basic statutory test of factual causation. The question of whether a permanent impairment is caused by a work injury is a matter an approved medical specialist, or an appeal panel, is entitled to consider: Bindah v Carter Holt Harvey Woodproducts Australia Pty Ltd [2014] NSWCA 264 at [112]. Indeed one might say it was necessary for Dr Weisz to consider questions of causation to discharge his statutory remit, just as the appeal panel considered them in carrying out its review.
16. In my judgment, however, this error was not material to the Appeal Panel's decision. The material errors in Dr Weisz's replacement MAC were going beyond the terms of the referral and failing to make a deduction under s 323 WIM Act and I am satisfied the Appeal Panel was correct to so find.
17. For these reasons I am not satisfied that Ground 1 has been made good. To summarise what I have written I am not persuaded that the Appeal Panel wrongly concluded that in the replacement MAC Dr Weisz had assessed the whole person impairment resulting from all of the 1993 injury, the nature and conditions of employment in the interval and the 2011 injury. I am satisfied that the Appeal Panel were correct to so hold. Dr Weisz made changes to the first MAC in response to the legal arguments of the parties in the process of correcting what was said to be obvious errors in the first MAC. Frankly, he was not provided with much help in identifying the obvious errors given the competing positions of the parties. But however that may be, and notwithstanding him withdrawing the second and fourth sentences from paragraph 10(a) of his reasons, it is clear that he regarded Mr Gatt's whole person impairment as the end result of the 1993 injury, the intervening nature and conditions of employment, and the 2011 injury. He, like Dr Millons and Dr Pillemer, did not regard the 1977 injury as causative of Mr Gatt's impairment. The Appeal Panel were correct in their assessment and understanding that Dr Weisz had not in substance changed his views. They correctly understood that Dr Weisz was still proceeding on the basis that the consequences of each of the injuries he identified could not be sensibly separated. This is what the Appeal Panel meant when they said (at Reasons [77]) that Dr Weisz was assessing the impairment resulting from a deemed date of injury in December 2011.
18. That the Appeal Panel wrongly reiterated the fourth sentence from paragraph 10(a) of the first MAC at Reasons [45] was, as I have said, a mere error in composition. The Appeal Panel was clearly aware that the sentences had been withdrawn. In my judgment it makes no difference that in making their own assessment they adopted Dr Weisz's approach expressed in that fourth sentence from paragraph 10(a) in the first MAC. They made it clear that they agreed with what Dr Weisz had done then, even if the first MAC was of no legal effect; it remained before them as part of the material they were asked to consider.
19. I have accepted that the Appeal Panel was wrong to say that questions of aggregation and causation were not the concern of an approved medical specialist carrying out a medical assessment under s 321. But, in my judgment this was not a material error on the part of the Appeal Panel as there were other grounds correctly identified: Hossain v Minister for Immigration and Border Protection [2018] HCA 34; (2018) 92 ALJR 780.
20. I am not satisfied that it was an error for the Appeal Panel to decide to make a deduction in respect of a pre-existing condition of osteoarthritis. As I have attempted to point out in the course of these reasons already, in substance this was a ground advanced by the employer. The employer's complaint at its essence was that no s 323 deduction had been made at all in the face of clear history of previous material injuries. The osteoarthritic changes in Mr Gatt's right shoulder were pre-existing pathology when viewed from the standpoint of the 2011 injury. It is also fair to call them pre-existing degenerative changes. Neither of these expressions were terms of art nor were they inconsistent with the different language of s 323 WIM Act. Importantly at a factual level (at Reasons [96]) it is clear that the Appeal Panel concluded that this pre-existing pathology and pre-existing degenerative changes, were associated with Mr Gatt's work related injuries. At Reasons [96], extracted at [46] above, the Appeal Panel said when rejecting an argument that statutory assumption under s 323(2) WIM Act should be made: It is clear that the respondent had longstanding degenerative changes on a background of prior injuries. As I have said, this view is entirely consistent with that of the medical referees for the parties, Dr Millons and Dr Pillemer, as well as the treating doctors whose reports were before Dr Weisz and the Appeal Panel.
21. Were I wrong in the view expressed in the immediately preceding paragraph, it needs to be emphasised that s 323(1) requires a deduction to be made "for any proportion of the impairment that is due to any previous injury (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1997 Act) or that is due to any pre-existing condition or abnormality" (my emphasis). The section makes no distinction between previous work related injury, on the one hand, and pre-existing condition or pre-existing abnormality, on the other. Whether the condition of Mr Gatt's shoulder as at 9 April 2014 before he underwent the surgery is regarded as the product of the series of work related injuries with the employer or as pre-existing pathology from a pre-existing condition or abnormality can make no practical difference to the assessment of WPI; particularly in circumstances where a single frank injury of 3 December 2011 was put forward as the sole relevant injury from which Mr Gatt's whole person impairment was said to result. With the claim framed in that manner, the 1993 injury and the subsequent nature and conditions of his employment as a rescue paramedic were previous injuries within the meaning of s 323(1) whether or not … compensation has been paid or is payable in respect of either or both of them under Division 4 of Part 3 WCA. And the law required any proportion of the impairment that is due to those previous injuries to be deducted. All medical experts agreed that Mr Gatt's impairment was due to those previous injuries in the sense that the pathology that gave rise to the necessity for the total shoulder replacement of April 2014 was the result of all of his work-injuries with the employer.
22. The point remains whether one considers the osteoarthritic changes shown on the December 2011 MRI scan as injurious consequences of the previous injuries or as a pre-existing condition or abnormality, as a matter of law, on the evidence before Dr Weisz and the Appeal Panel, s 323 WIM Act required a deduction to be made, and in the same proportion.
23. Ground 1 is rejected.

Ground 2 finding error in a non-existent version of the medical assessment certificate

1. Ground 2 focuses upon, what I have characterised as the error of composition (at Reasons [45]) by the erroneous re-iteration of the fourth sentence of paragraph 10(a) of Dr Weisz's first MAC while purportedly quoting from the replacement MAC. Ms Allars characterises this as jurisdictional error by the Appeal Panel misconceiving and misunderstanding its function. That sentence was a statement, I repeat for convenience, "the accident of 2011, if taken separately, would be a quarter of the assessed impairment". The withdrawal of this sentence by Dr Weisz in the replacement MAC was significant, according to the argument, because it justified the conclusion that no deduction was necessary by reason of a previous injury or pre-existing condition. The error was material because the Appeal Panel concluded that a deduction of three-quarters of the assessed whole person impairment should be made.
2. Ms Morgan argued that this "error" is not jurisdictional because it is obvious on the face of the Appeal Panel's reasons that it was aware that its task was to review the replacement MAC and not the first MAC.
3. I agree with the employer's argument. As I have said, the error is one of composition, in the nature of a slip or clerical error only. I am satisfied that the Appeal Panel (at Reasons [36]) (see [35] above) fully appreciated that the first MAC "has no standing".
4. I am not satisfied that the Appeal Panel assessed the deduction to be made under s 323 WIM Act at 75 per cent because they were mistaken about the content of paragraph 10(a) in the replacement MAC. The first MAC was before them and the members of the Appeal Panel agreed with the approach Dr Weisz had then taken, as they were entitled to do. Indeed, in substance they were entitled, having conducted their review in according with s 328(2) WIM Act, to decide that they agreed with the assessment made by Dr Weisz in his first MAC and that the opinions he expressed as to proportion of the WPI due to previous injuries and a pre-existing condition were correct.
5. I am not satisfied that Ground 2 is made out.

Grounds 3 and 4

1. Ms Allars dealt with Grounds 3 and 4 together in her written submissions and I will follow suit. The essence of this argument is that Reasons [93] - [94] properly understood, indicate that the Appeal Panel found that Mr Gatt's whole person impairment did not result from the 2011 injury at all. If this is so, there was no entitlement to permanent loss compensation resulting from that injury and accordingly no occasion to make a deduction under s 323 WIM Act. The jurisdictional error is characterised by learned Senior Counsel as the Appeal Panel misunderstanding its function and asking itself the wrong question. Reliance was placed upon Bindah v Carter Holt Harvey at [19], [28] Meagher JA (Ward JA agreeing at [31]; and Emmett AJA agreeing at [111], [120- [122].
2. Ms Morgan argued that even if Mr Gatt's submission is correct, the Appeal Panel "did not approach its task on the assumption that only with [the] surgery could [Mr Gatt] be assessed as having a whole person impairment as a result of the 3 December 2011 injury".
3. I am not satisfied that Ms Allars major premise, that the Appeal Panel found no relevant causal connection between the 2011 injury and the need for the shoulder replacement surgery is correct. To the extent to which the employer's argument tacitly accepts that proposition, I am not persuaded by it. In my judgment the argument overlooks Reasons [95] which where the Appeal Panel draw together the preceding paragraphs. It is set out in full at the foot of [46] above. The concluding sentence of Reasons [95] is in the following terms: Were it not for the presence of the degenerative changes, the incident in 2011 would not have been sufficient to give rise to the need for surgery. This is in fact a finding that the 2011 injury was a cause of the need for surgery, but not the sole cause. The 2011 injury may not have been "the pivotal incident giving rise to the need for surgery" (Reasons [95]), but reading the reasons fairly and as a whole, the Appeal Panel found it was a necessary condition of the need for surgery and accordingly the whole person impairment resulted from the 2011 injury, but not solely.
4. I reject Grounds 3 and 4

Ground 5 denial of procedural fairness

1. This ground is concerned with that part of Ground 1 which I have summarised at [55(c)] above. Ms Allars argues that the Appeal Panel's findings in relation to pre-existing pathology and pre-existing degenerative changes at reasons [89] and [96] were a critical issue not raised by the parties and not disclosed to them by the Appeal Panel. Reference was made to Markovic v Ridges Hotels Ltd [2009] NSWCA 181 at [35].
2. Ms Morgan joins issue and submits, for the contentions advanced by them for the purpose of Ground 1, this issue was fairly raised in the application for appeal and in the submissions made to the Appeal Panel.
3. I agree with the employer's submissions. The existence of the osteoarthritic changes in Mr Gatt's right shoulder was not a new issue. As I have attempted to demonstrate in relation to Ground 1, each of the medical referees and the treating doctors whose reports were before Dr Weisz and the Appeal Panel discussed the existence of these changes, their relationship to the work injuries and the part they played in the necessity for Mr Gatt to undergo prosthetic shoulder replacement surgery. This is not a case where the Appeal Panel raised an important issue for themselves without notice to the parties. I am not of the view that the Appeal Panel "misconceived their role, the nature of their jurisdiction and their duty": Markovic at [35].
4. As I have already said at Reasons [96] the Appeal Panel demonstrated that they appreciated that the osteoarthritic changes to Mr Gatt's right shoulder were associated with ("on the background of") a number of prior work injuries.
5. I am not satisfied that Ground 5 has been made out.

Ground 6 error of law on the face of the record

1. Grounds 1 to 4 are reiterated as errors of law on the face of the record. As I am not satisfied that any of these grounds have been made out as material errors I reject Ground 6. Errors of law on the face of the record, also attract an order in the nature of certiorari only if material: Australian Broadcasting Tribunal v Bond (1990) 170 CLR 321; [1990] HCA 33 at 353.
2. My orders are: 1. The relief sought in the Amended Summons is refused; 2. Proceedings dismissed; 3. The plaintiff to pay the first defendant's costs of the proceedings.

Addendum

1. In Attorney-General for the State of New South Wales v Quin (1990) 170 CLR 1 at 35 - 36 Brennan J said: The duty and jurisdiction of the court to review administrative action do not go beyond the declaration and enforcing of the law which determines the limits and governs the exercise of the repository's power. If, in so doing, the court avoids administrative injustice or error, so be it; but the court has no jurisdiction simply to cure administrative injustice or error. In arriving at my decision, I have attempted assiduously to apply this precept. But I cannot leave the case without observing that it seems a remarkable outcome that a person in Mr Gatt's position should be adjudged entitled to no permanent loss compensation at all for what is obviously, in ordinary language, a seriously injured right shoulder. I say this because on the whole of the material before Dr Weisz and the Appeal Panel it is glaringly apparent that the condition of Mr Gatt's right shoulder which necessitated the prosthetic shoulder replacement surgery in 2014 was due to work injury suffered in the course of his employment with the employer between 1993 and 2011, with perhaps some ongoing exacerbations from time to time thereafter due to the heavy nature of much of his work. To use a sometimes overworked expression, the evidence was all one way that Mr Gatt made a complete recovery from the effects of the 1977 injury and the resulting surgical repair then. I interpolate that injury was suffered in the course of his employment with another State government department. All of the doctors who examined Mr Gatt were impressed, as I have already said, by his high motivation to work notwithstanding the pain and restriction due to his injuries.
2. During the course of the hearing, I asked Senior Counsel for the employer (26.35T; 32.42T) about the legal entitlement of an injured worker to claim permanent loss compensation resulting from a series of work injuries straddling the date of commencement of the relevant provisions of the Workers' Compensation Legislation Amendment Act 2001 (NSW) and by Workers' Compensation Legislation Further Amendment Act 2001 (NSW), namely 1 January 2002. In substance I was informed that in the case of a disease-injury as defined in s 4(b)(i) or (ii) with a deemed date of injury fixed pursuant to s 15 or s 16, all of WCA, the injured worker concerned would be entitled to claim the total compensation for all of the whole person impairment resulting from the disease-injury. This seems broadly consistent with the terms of s 68B WCA referred to in the note at the foot of s 323 WIM Act. Otherwise, of course, s 323 WIM Act applies.
3. Although it was neither necessary nor appropriate to canvass before me the reasons for the decision to present Mr Gatt's claim as one founded upon a "frank injury" of 3 December 2011 alone, I can only assume that it was made for sound legal or forensic reasons. However that may be, the legal outcome here strikes me as most unfortunate involving, as it does, the law denying an obviously deserving claimant the full lump sum compensation he could otherwise legitimately expect to receive for an obviously serious consequence of a series of injuries received at work with the one employer.

Amendments 30 April 2019 - Paragraph 3: Last sentence - the words "and applies to Mr Gatt's claim" removed. Paragraph 3: 3 new sentences added to the end of this paragraph. Paragraph 22: "1 January 2012" changed to "1 January 2002" Paragraph 94: Last sentence - the words "lump sum compensation" replaced with "the full lump sum compensation he could legitimately expect to receive". 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: 30 April 2019