MATTER : Application for a Writ of Certiorari against the MEDICAL ASSESSMENT PANEL constituted pursuant to s 93D(11) of the Workers' Compensation and Rehabilitation Act 1981 (WA) consisting of Dr F Heyworth (Chairman), Dr E Gabbay and Dr M K Tandon

Workers' compensation - Prerogative writ - Certiorari - Determination by Medical Panel under s 36 - Clinical examination and observations by Panel - Adequacy of reasons for determination - Attorney General appearing by counsel as amicus curiae, ability of amicus curiae to adduce evidence - Points not taken before Tribunal or by respondent to application - Obligation for Panel to give reasons for decision

Workers' Compensation and Rehabilitation Act 1981, s 93D(11)

Ainsworth v Criminal Justice Commission [1992] HCA 10; (1992) 175 CLR 564

Craig v South Australia [1995] HCA 58; (1995) 184 CLR 163

CSR Ltd & Anor v The Medical Panel, unreported; FCt SCt of WA; Library No 9097; 11 October 1991

Fremantle Foundry and Engineering Co Pty Ltd v Medical Panel, unreported; FCt SCt of WA; Library No 9200; 17 December 1991

Harvey v The Racing Penalties Appeal Tribunal of Western Australia & Anor [2000] WASC 299

Hot Holdings Pty Ltd v Creasy [2002] HCA 51; (2002) 77 ALJR 70

R v Liverpool Corporation; Ex parte Liverpool Taxi Fleet Operators' Association [1972] 2 QB 299

R v Minister for Sea Fisheries; Ex parte National Australia Bank [1991] Tas R 70

R v Toohey; Ex parte Northern Land Council [1981] HCA 74; (1981) 151 CLR 170

Re Anastas & Ors; Ex parte Welsby [2001] WASC 178

Re Monger; Ex parte Cargo Enterprises Pty Ltd [2001] WASC 19

Re Monger; Ex parte Ivey [1999] WASC 250

Re Smith; Ex parte Rundle (1991) 5 WAR 295

1 EM HEENAN J: Since December 1999, the applicant, Eric Joseph Symons, has been seeking a determination of his claim that he has a "degree of disability" of not less than 16 per cent, and, therefore, a "significant disability" within the meaning of s 93E(4) of the Workers' Compensation and Rehabilitation Act (1981) ("the Act"). As his employer disputes the existence of such a significant disability, or any disability, the determination of this question in the affirmative is an essential prelude to the prosecution by the applicant of an action for damages for alleged negligence or other breach of duty against the employer in order to seek damages at common law - s 93E(3) of the Act.

2 In accordance with the provisions of the Act, this dispute was referred by the Director of Conciliation and Review ("the Director") to a Medical Panel for determination as provided in s 36 of the Act. On 7 November 2000, a Medical Panel so appointed, made a determination that the degree of the applicant's disability as assessed in accordance with s 93D(2) of the Act was 10 per cent, that is, less than the minimum 16 per cent disability which must be established before an action for common law damages may be pursued. The applicant sought a writ of certiorari to quash this determination on the grounds, inter alia, that the degree of disability so found by the Medical Panel had not been reached in accordance with the Act and was, therefore, invalid. That contention by the applicant succeeded and, by a decision of the Full Court (Steytler and Wheeler JJ and Burchett AUJ) of 12 September 2001 - Re Medical Panel; Ex parte Symons [2001] WASCA 280, that determination was quashed leaving the dispute to be determined afresh.

3 By a notice dated 12 February 2002 the Director again appointed a Medical Panel, in accordance with s 93D(11) of the Act, to determine the dispute about whether the degree of disability of the applicant was not less than the relevant level as defined by s 93D of the Act. The Medical Panel appointed to determine this dispute, which I shall call the "second Medical Panel", comprised as chairman, Dr Heyworth (who had presided over the first Medical Panel), and Drs Gabbay and Tandon neither of whom had sat on the first Panel. The second Medical Panel made a determination dated 20 March 2002, that the degree of the applicant's disability, as assessed in accordance with s 93D(2) of the Act, was 15 per cent.

4 The order nisi for writ of certiorari to quash the second determination was granted by Miller J on 31 October 2002.

5 Before examining the grounds upon which certiorari is sought by the applicant it is necessary to set out more fully the events which have led to the applicant's claim. These were described by Steytler J (with whom Wheeler J and Burchett AUJ agreed) when the Full Court quashed the first determination of the Medical Panel, as follows (at [2] - [4]):

"The applicant suffers from lung cancer, pleural disease and asbestosis. He believes that this was caused by his exposure to asbestos while employed as a truck driver in the 1950's by a company known as Manford Property Services Pty Ltd ('Manford Property'). He wants to sue Manford Property for damages. However, by s 93E(3) of the Act, he can only be awarded damages at common law if certain conditions are met. One of these (being the only relevant one for present purposes) is that he has a 'significant disability'. He will, by virtue of s 93E(4), have a significant disability if the degree of disability suffered by him is agreed or determined to be not less than 16 per cent and the agreement or determination is recorded in accordance with the Workers' Compensation and Rehabilitation Regulations (1982) ('the Regulations').

The applicant contends that his afflictions are such that his degree of disability is not less than 16 per cent. However Manford Property disputes this. In those circumstances the applicant was entitled, by s 93D(5) and (6) of the Act, if he could obtain a doctor's opinion indicating that his degree of disability was not less than 16 per cent, to refer the question as to his degree of disability to the Director of Conciliation and Review ('the Director') appointed in accordance with Div 1A, Pt V of the Act. He did obtain such an opinion. He consulted Dr A W Musk, a physician who has expertise in the field of respiratory medicine. Dr Musk provided him with a report, dated 24 February 2000, in which he concluded that the applicant's degree of disability was about 20 per cent. The applicant delivered the report to the Director.

The Director, once he had received Dr Musk's report, notified Manford Property of its contents. However it continued to insist that the applicant's degree of disability was less than 16 per cent. A 'dispute' consequently arose for the purposes of s 93D(8) of the Act. It was not resolved by agreement. Because the dispute related to a disability mentioned in s 33, s 34 or s 35 of the Act (being one caused by, inter alia, lung cancer and asbestosis), the dispute was required, by s 93D(11), to be referred to a medical panel for determination as described in s 36 of the Act. That section provides for references to a medical panel comprising two or three physicians nominated from amongst those who specialise in diseases of the chest or in occupational diseases, one of whom must specialise in diseases of the chest."

6 On such a reference the degree of the worker's disability must be assessed in accordance with s 93D(2) - see s 93D(11). In such circumstances the degree of disability of the worker is to be assessed, insofar as Sch 2 applies, in the manner prescribed by s 93D(2)(a); to the extent that Sch 2 does not apply, in accordance with the degree of permanent impairment assessed in accordance with the AMA Guidelines; or if the AMA Guidelines do not apply then in accordance with the Regulations. In this case neither Sch 2 of the Act nor the AMA Guidelines applied to the disability alleged. At the time of the first determination there was nothing in the Regulations which prescribed how the degree of such a disability should be assessed. In that hiatus the first Medical Panel made its determination of the appellant's degree of disability on criteria which, while not identified, were not criteria specified by s 93D(2). As that was not a determination made in accordance with the Act, it followed that the first Medical Panel necessarily acted in excess of the jurisdiction conferred by the Act and so certiorari issued to quash that determination.

7 Since then, however, the Regulations have been amended and reg 14 of the Workers' Compensation Amendment Regulations (2000) requires that the method of assessment to be employed by the second Medical Panel is the method provided in the American Medical Association's Guides to the Evaluation of Permanent Impairment (4th ed) "USAMA Guide".

8 The second Medical Panel assessed the applicant on 20 March 2002 at a hearing at the Perth Chest Clinic at 17 Murray Street. Mr Symons was accompanied, at that assessment, by his own medical practitioner, Dr Deleuil, who was entitled to be present - s 37 - and who had previously prepared and submitted to the Panel his own report of the applicant's respiratory impairment, based on the USAMA Guide. Dr Deleuil has made an affidavit outlining his discussions with the members of the Panel and the oral explanation given by them at the time their determination was made. The role of Dr Deleuil will be described more fully later.

9 Following the determination of the second Medical Panel, the solicitors for the applicant wrote to the chairman of that Panel requesting reasons "sufficient to disclose the basis of the determination" but, by letter dated 23 April 2002 from the Manager Operational Planning Review and Support of the Industrial Diseases Medical Panel, the applicant was advised that no written reasons would be provided and that legal advice provided to the Panel was that the Panel was under no statutory obligation to give written reasons for its determination. It is to be noted that a similar request for reasons for decision had been made of the first Medical Panel and had also been refused. That refusal was an additional ground relied on by the appellant for seeking a writ of certiorari to quash the determination of the first Panel but, that ground was not dealt with by the decision of the Full Court, it being sufficient to establish the right to certiorari that the determination had been carried out otherwise than in accordance with s 93D(2) of the Act.

10 On the return of the first order nisi for certiorari before the Full Court, the employer Manford Property sought and was granted leave to intervene by counsel and was heard in opposition to the application. In the present proceedings the employer has not sought to intervene or be heard either on the application for the order nisi or on the return of the order nisi before me. The respondent, the Medical Panel, however has filed a notice of intention to abide by the Court's decision and was not represented at the hearing.

11 However, in the absence of any representation for the employer the Attorney-General of Western Australia appeared by counsel and sought leave to appear as an amicus curiae. This was opposed by counsel for the applicant and, in elaborating upon the application, counsel for the Attorney-General indicated that the Attorney would seek to adduce affidavit evidence from the Director of Conciliation and Review not only in opposition to the application for certiorari on its merits but also to support a submission that the original referral to the first Medical Panel, and the determination of the second Medical Panel, were invalid and ineffective because of the absence of sufficient medical evidence to sustain the referrals in accordance with the principles established by the decisions of the Full Court in Re Monger; Ex parte Dutch [2001] WASCA 220; (2001) 25 WAR 96 at 117 - 123 and Re Monger; Ex parte United Construction Pty Ltd [2002] WASCA 253 at [42] - [43].

12 Accordingly, questions arose as to whether leave should be granted to the Attorney-General to appear at all, and if so, whether leave should be restricted and whether or not, as amicus curiae, the Attorney-General should be permitted to adduce evidence in opposition to the application. After hearing initial submissions I decided that I should permit counsel for the Attorney-General to participate in the hearing and to advance all submissions which she had been instructed to put, but that I would reserve my decision upon the basic questions of whether or not the amicus curiae should be heard, and if so, the extent to which submissions would be received or evidence admitted. On this basis the affidavit evidence sought to be adduced by the Attorney-General was tendered and the submissions made were accepted provisionally.

"1. A Medical Panel constituted pursuant to s 93D(11) of the Workers' Compensation and Rehabilitation Act (1981) (WA) ('the Act') consisting of Dr F Heyworth (Chairman), Dr E Gabbay and Dr M K Tandon ('the Medical Panel') do show cause before the Full Court of this Honourable Court why a writ of certiorari should not be issued against it quashing its determination that in response to the question 'What is the degree of the applicant's disability as assessed in accordance with s 93D(2) of the Act?' referred to the Medical Panel by the [Director] of Conciliation and Review appointed in accordance with the Division 1A Part V of the Act ("the Director") certified on 20 March 2002 that the applicant's degree of disability assessed in accordance with s 93D(2) of the Act was fifteen (15) per cent ("the determination") on the grounds that the Medical Panel:-

(i) in determining the method to be used to assess the applicant's degree of disability was bound by the methods of assessment set out at s 93D(2) of the Act, and s 93D(2) of the Act read with regulation 14 of the Workers' Compensation Amendment Regulations (2000) (WA) requires that the method of assessment to be employed by the Medical Panel is the method provided in the American Medical Association's Guides to the Evaluation of Permanent Impairment (4th edition). ("The prescribed method");

(ii) failed to carry out its assessment in accordance with the prescribed method in that:

(a) it applied predicted levels of lung function ("non-prescribed background levels") other than those set out in the USAMA Guide;

(b) failed to take into account the applicant's Measured Exercise Capacity ("VO2 Max") when determining the whole body impairment pursuant to Table 8 page 5/162 of the USAMA Guide;

(c) failed to take into account that the applicant's condition is deteriorating when determining a degree of disability;

(iii) was convened by the same Chairperson as had already sat on an earlier Medical Panel the decision of which Panel had been quashed by this honourable Court and which, because of the Panel's earlier detailed consideration of the matter, meant that a fair-minded person might reasonably apprehend or suspect that the Medical Panel had pre-judged its determination, or made its determination influenced by the earlier Panel's deliberations, and

(iv) in making its determination acted ultra vires.

2. In the alternative and upon the return of the order nisi, an order be made staying the determination, and that the Medical Panel provide its reasons for the determination which reasons declare the method of assessment adopted, the evidence relied upon and the basis for the determination."

14 Although the order nisi directed that the application for certiorari should be returnable before the Full Court, the applicant and the proposed intervener had been content for it to be heard and determined before me as a single Judge of the court. In this regard it is to be noted that the applicant applied for the order nisi to be entered for hearing before a single Judge when it was listed on 8 November 2002 and that the order nisi was listed accordingly. As return of an order nisi before a single Judge is a course which is permitted by Rules of the Supreme Court O 56 r 2 and r 3 I consider that I should treat the order nisi as having been amended in this regard on the application of the parties.

15 Consequently, the following issues are presented for decision on this application:

1. Whether the Attorney-General as amicus curiae may be permitted to adduce evidence in opposition to the application and to raise issues concerning:

• the jurisdiction of the Director to refer the original dispute to the Medical Panel, and to refer that dispute again to the second Medical Panel after the decision of the Full Court, in the light of the decision in Re Monger; Ex parte Dutch (supra);

• whether the Attorney-General may be permitted to make submissions on the application and effect of the USAMA Guide;

• whether the Attorney-General may be permitted to make submissions on the alleged obligation of the Medical Panel to provide reasons for its determination.

2. Whether, on a proper interpretation of reg 14 and the USAMA Guide a Medical Panel was authorised to employ background levels of lung function used by the Sir Charles Gairdner Hospital in Perth rather than the background levels of lung function referred to in the USAMA Guide.

3. Whether the Medical Panel was in error in failing to apply the USAMA Guide in its entirety by overlooking measured exercise capacity (VO2) and in failing to give the weight to the applicant's deteriorating condition.

4. Whether the Medical Panel was obliged to give reasons for its determination.

The role of amicus curiae and the extent to which an amicus may make submissions

16 The application by the Attorney-General was for leave to appear as amicus curiae. No submission was made that the Attorney-General was entitled to appear, as of right or by leave, as an intervener in the proceedings.

17 It has long been recognised that the Attorney-General may intervene in proceedings before court, even civil proceedings between private parties, in order to advance or to protect some public right or interest: Attorney-General (Commonwealth) v T & G Mutual Life Society Ltd [1978] HCA 24; (1978) 144 CLR 161 at 166; Attorney-General (Commonwealth) ex rel McKinlay v The Commonwealth [1975] HCA 53; (1975) 135 CLR 1 at 26. This appears to be an application of the principle that the Attorney-General, alone, may bring or defend an action involving a public right or remedy, a public nuisance or a breach of public statutory interests: Attorney-General v Oxford, Worcester and Wolverhampton Railway Co (1854) 2 WR 330; Attorney-General v BP (Aust) Ltd [1964-1965] NSWR 2055; (1964) 83 WN (Pt 1) (NSW) 80; Hoffman-La Roche & Co AG v Secretary of State for Trade and Industry [1975] AC 295 at 363; Attorney-General (NSW) v Brewery Employees Union of NSW [1908] HCA 94; (1908) 6 CLR 469 at 499 - 500; 552 - 553; Anderson v The Commonwealth [1932] HCA 2; (1932) 47 CLR 50 at 52 and Tasmania v Victoria [1935] HCA 4; (1935) 52 CLR 157 at 171; 186 - 188. However, where no public right, interest or remedy is concerned the Attorney-General has no right of action ex officio nor any right to intervene in litigation between parties: Cooney v Ku-Ring-Gai Corporation [1963] HCA 47; (1963) 114 CLR 582; The Commonwealth v Rhind [1966] HCA 83; (1966) 119 CLR 584; Gouriet v Union of Post Office Workers [1977] UKHL 5; [1978] AC 435 at 500 and Attorney-General; ex rel Spalding Rural District Council v Garner [1907] 2 KB 480 at 487. A person accepted as an intervener becomes a party to the proceedings with all the privileges, and liabilities, of a party. Hence an intervener can appeal, tender evidence and participate fully in all aspects of the argument: Attorney-General (Commonwealth) v The Queen (the Boilermakers' case) [1957] HCA 12; (1957) 95 CLR 529 and Attorney-General for Ontario v Winner [1954] AC 541 and Corporate Affairs Commission v Bradley [1974] 1 NSWLR 391 per Hutley JA at 396.

18 By contrast, the role of an amicus curiae is markedly different. The amicus curiae does not have any rights or interests affected by the litigation which would be sufficient for the amicus to be joined as a party or, if the Attorney-General, which would justify intervention. The role of the amicus, as his name suggests, is to assist the court by ensuring that the court is properly informed of matters which should be taken into account in reaching its decision and this may well be of assistance to the court where the litigation involves an important question of law affecting persons other than the parties, especially disadvantaged persons. It is often a convenient course to allow an address by an amicus curiae where one of the parties to the litigation or appeal is unable or unwilling to arrange for legal representation, or where they may be no contradictor to ensure that opposing arguments are brought to the attention of the court: Dobree v Hoffman (1996) 18 WAR 36. However, an amicus curiae does not become a party to the proceedings and may not appeal: Day v Day [1957] P 202; Corporate Affairs Commission v Bradley [1974] 1 NSWLR 391 at 396 and 399. The latter decision was cited, with evident approval, by Dawson J in Levy v The State of Victoria (1997) 189 CLR 579 at 604 - 605. As there is no right of appearance it is entirely for the court to decide whether or not an amicus curiae should be heard and, if so, to what extent and on what aspects of the case: Brandy v Human Rights and Equal Opportunity Commission [1995] HCA 10; (1995) 183 CLR 245 at 258.

19 Another comparison of the respective roles of an intervener and an amicus curiae was undertaken by the Full Court of the Federal Court of Australia in US Tobacco Co v Minister for Consumer Affairs (1988) 20 FCR 500 where, at 533 - 534, Davies, Wilcox and Gummow JJ undertook a detailed review of the authorities and extra judicial writings on the subject. This analysis was obiter because the court was satisfied that the party concerned had an interest which justified it being joined in the proceedings and exercising the full rights of a party after that joinder. However, while stressing that no fixed or inflexible practice about the scope and role of an amicus curiae had emerged from the authorities and that the discretion of the court to permit an amicus curiae to be heard remained a flexible one, their Honours stressed that the conventional view was that an amicus curiae could not adduce evidence or make any contribution to the record, give discovery or inspect discovered documents. The proposed tender of evidence by an amicus curiae was rejected in Bropho v Tickner [1993] FCA 25; (1993) 40 FCR 165 per Wilcox J at 173. In those cases where an amicus has been allowed to address the court his role has, generally, been confined to addressing points of law although, occasionally, the court has been willing to accept the assistance of an amicus curiae in referring to issues of fact, while recognising this to be something of an expansion of the usual practice: Johnson v Sammon (1974) 7 SASR 431 at 433 - 435.

20 Without excluding the possibility that there may occasionally be a case which may justify the course, my reading of the authorities leads me to the conclusion that it will be a rare and exceptional case in which an amicus curiae is permitted to adduce evidence or raise a special defence. The disinclination of the court to allow such a role is consistent with the rule that, in litigation in which only the rights of the contesting parties are affected, the cause should be accepted and decided by the court on the issues and upon the evidence which the parties themselves present for decision.

21 In the present case, where the employer, who was the respondent to the application before the Workers' Compensation Review Directorate by the appellant to have the extent of his disability determined, in the events which happened, by the Medical Panel was not made a party to this present application for certiorari (although the employer had sought to intervene and was joined as a party at a previous proceedings for certiorari to quash the determination of the first Medical Panel) it is certainly of assistance for this Court to have the benefit of considered submissions by counsel for the Attorney-General as amicus curiae on the general principles to be applied in this case and upon the particular complexities of the provisions of the Act and the Workers' Compensation and Assistance Regulations to the extent that, in the present instance, they incorporate by reference a method for determining disability directed by the USAMA Guide. To that extent, therefore, I am considerably assisted by and appreciate the submissions which have been offered by the amicus curiae. Beyond this, however, I do not consider that I should permit the amicus curiae to go and, in particular, I am satisfied that in this particular litigation I should not allow the tender of evidence by the amicus curiae, as he is not a party to the proceedings.

22 Similarly, I do not consider that I should permit the amicus curiae to raise, for the first time at this stage of the dispute between the appellant and his employer, the question of whether or not the Director was empowered to refer the question of disability to the Medical Panel where it is now sought to be submitted, that there was insufficient medical evidence to justify the Director referring the question of the degree of disability for resolution pursuant to s 93D of the Act: Re Monger; Ex parte Dutch [2001] WASCA 220; (2001) 25 WAR 96.

23 Not only do I consider that the amicus curiae is not entitled to raise a substantive issue of that nature in the present proceedings, but I also consider that even if that matter were to be raised by a party with a sufficient interest at this stage of the litigation, or indeed subsequently, it is unlikely to be upheld. This is because the decision of the Full Court in Re Monger; Ex parte Dutch (supra) was decided on 30 July 2001, that is before both the hearing and the delivery by the Full Court of its decision in the first certiorari application to quash the earlier finding of the Medical Panel (Re Medical Panel; Ex parte Symons [2001] WASCA 280) which was heard and determined, respectively on 6 and 12 September 2001. The decision of the Full Court on that first application was to quash the determination of the Medical Panel. Steytler J, with whom Wheeler J and Burchett AuJ agreed, observed at [18]:

" ... Because the legislative omission to which I have referred has since been remedied, a fresh determination can now be made in accordance with the requirements of the Act."

In the circumstances which then existed, this can only mean that the referral by the Director to a Medical Panel which had, by then occurred, remained unresolved and still remained to be resolved in accordance with the law as decided by the Full Court. Had the employer desired to challenge the decision of the Medical Panel, or of the Director to refer the "dispute" to the Panel on any of the grounds upheld in Re Monger; Ex parte Dutch (supra) then that should have been done in those proceedings and, by failing to raise or take such a point when the validity of the determination of the Medical Panel was directly in issue, I consider that the employer has foregone the opportunity to do so and cannot now be permitted to raise such an issue, when it was not raised when the validity of that determination was being adjudicated: Port of Melbourne Authority v Anshun Pty Ltd [1981] HCA 45; (1981) 147 CLR 589 and Henderson v Henderson [1843] EngR 917; (1843) 3 Hare 1000; 67 ER 313.

24 Even if it were to be submitted (and it was not submitted here) that at the time when the first certiorari application was before the Full Court and before the decision of the Full Court had been given, the respondent was not aware of, or fully aware of, the potential implications of the decision in Re Monger; Ex parte Dutch (supra) that would not be a sufficient reason to allow the introduction of an objection, at this stage, to the validity of the reference by the Director to the Medical Panel again because no such point had been raised by the respondent employer at the proper time. A new decision of a court binding upon a court or tribunal which has heard and determined a cause, in a manner that may have relied upon a different understanding of the law than that determined by a recent binding decision, is not a ground for reopening a decision made on a different assumption once that litigation has concluded: Piening v Wanless [1968] HCA 7; (1968) 117 CLR 498, per Barwick CJ at 503 and 506, Menzies J at 509 - 510, and Windeyer J at 511.

25 Accordingly, I refuse to admit into evidence on this application the affidavit of R E Monger and its annexures sworn 27 March 2003, which were tended provisionally by counsel for the amicus curiae. Nor will I accept the objection provisionally advanced by the amicus curiae to the validity of the referral by the Director of Work Cover to the second Medical Panel of the "dispute" about the extent of the appellant's alleged disability, which relies on the principles upheld by the Full Court in Re Monger; Ex parte Dutch (supra).

26 Therefore, this leaves for consideration the submissions made by counsel for the amicus curiae about the methods prescribed by the Act and Regulations for the determination of disability due to reduction in respiratory function, and on the question of whether or not the Medical Panel was obliged to provide reasons for its determination. As I have already said, I appreciate the assistance which had been provided by the amicus curiae in addressing those issues.

Disability due to reduction in respiratory function

27 As previously noted, the decision of the Full Court to quash the determination of the first Medical Panel was because the method for assessing a worker's disability in accordance with s 93D(2) of the Act had not been employed. That was not due to any failure by that Medical Panel to follow a prescribed procedure but, rather, it was due to an omission in the Act and Regulations to provide a method of assessment for a disability due to a reduction in respiratory function. As explained by Steytler J in the earlier decision (at [7] - [14]) Sch 2 of the Act did not provide a method for the assessment of this particular disability, nor did the AMA Guidelines provide any such method. This meant that, in the situation as it then existed, the Medical Panel was obliged to carry out the assessment of the disability in accordance with the Regulations (s 93D(2)(c)). But, being unable to do so, it devised a clinical assessment which the Panel thought to be satisfactory but which was not authorised, and hence was beyond its jurisdiction. Since then the Workers' Compensation and Rehabilitation Regulations (1982) were amended (Gazette 17 November 2001 p 6312 - 6313) to insert reg 191A as follows:

"191A Guides for assessing degree of disability

(1) The first edition is prescribed for the purpose of the definition of 'AMA Guides' in section 93A of the Act.

(2) To the extent, if any, the neither section 93B(2)(a) nor (b) of the Act applies to the assessment of the degree of disability of a worker for the purposes of s 93E, the degree of disability is to be assessed in accordance with the American Medical Association's Guide to the Evaluation of Permanent Impairment (4th Edition)."

So it is to the American Medical Association's Guides to Evaluation of Permanent Impairment that reference must be made for the determination of the applicant's alleged disability. The chapter of the USAMA Guide, dealing with "The Respiratory System", is Annexure EJS15 to the affidavit of the applicant sworn 17 September 2002 in support of the present application. It contains a lengthy and detailed explanation of methods used for the recognition and assessment of respiratory abnormalities of various kinds. The physiological tests for pulmonary function; the techniques, use and interpretation of these tests in order to obtain a quantitative evaluation of respiratory capacity are described in Pt 5.2 of the USAMA Guide.

28 Essentially, the method followed is to take a number of specific measurements of the subject's pulmonary function under controlled conditions and with standardised equipment and then to compare these with reference values to extract a series of ratios which then, collectively, form the basis of the diagnostic assessment according to a categorisation contained in Table 8 of the Guideline. The AMA Guide contain a series of tables of reference values for men and women with which (subject to certain exceptions) the personal test results of the subject are to be compared. It is the comparison made in the present case between the personal test results obtained from the examination of the applicant, Symons, and "reference values" which the Medical Panel took, not from the USAMA Guide but from Australian reference tables which is the focus of the contention in this case.

29 The approach to physiological testing is apparent from the following passages in the USAMA Guide:

"Forced Respiratory Maneuvers (Simple Spirometery)

Physiologic testing of pulmonary function is the quantitative basis on which the evaluation of respiratory system impairment rests. A forced expiratory maneuver must be performed during the examination and evaluation of each patient for permanent pulmonary impairment. The testing and spirometery must be performed on standardised equipment calibrated according to, and using the techniques described in, the 1987 ATS Statement on Standardisation of Spirometery.

Measurements are made from at least three acceptable spirometric tracings of forced expiration: forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the ratio of these measurements (FEV1/FVC). The maneuvers should be performed at least three times, and the results of the two best FVC efforts should be within 5% of each other. The tracing with the highest FVC and the tracing with the highest FEV1 should be used to calculate the FEV1/FVC ratio even if these measurements occur on different expiratory efforts.

...

Measurements of FVC and FEV1 should be compared to the values obtained from healthy subjects or reference values. Such values for both men and women are presented in Tables 2 through 5 (pp 156 through 159). To find the average or 'predicted value', find the patient's age in the left-hand column and the height along the top row; the predicted value lies at the intersection of the appropriate row and column.

North American whites have larger spirometric values for a given age and height than North American blacks. According to the ATS Taskforce For Interpretation of Pulmonary Function, the following adjustments for predicted lung evaluation in black persons should be followed: values given for predicted normal FVC in Tables 2 and 3 should be multiplied by 0.88; values for predicted normal FEV1 in Tables 4 and 5 should be multiplied 0.88; values for normal single breath carbon monoxide diffusing capacity (Dco) in Table 6 (above) should be multiplied by 0.93.

Current information indicates there is a tendency for Hispanics, Native Americans, and Asians to have lower lung function values than North American whites. The cause and the magnitude of this difference are not yet well established, however, and no recommendation for the proportional adjustment of predicted lung function can be made at the present time."

The ASAMA Guide contains further observations relating to the measurement of Diffusing Capacity of Carbon Monoxide (Dco) and also includes a set of reference values for population-based results for Dco allowing a ratio to be established between the measured value of the subject and the predicted value similarly derived from the population-based reference values.

30 A further test is measured exercise capacity in order to determine the uptake of oxygen (VO2). Exercise capacity measurements are an adjunctive or accessory means of assessing the severity and cause of exercise intolerance and are not always used in the assessment of disability test. As will be described later, however, the measured VO2 max for Mr Symons was taken in his assessment but it was not compared with any predicted values and it is not possible to determine whether or not his VO2 max reading contributed, significantly, or at all to the vital assessment. However, nothing turns on that uncertainty in the present case. (The USAMA Guide specifically recommends measured exercise capacity testing to determine VO2 where the "physician has reason to believe that the usual test may have underestimated the impairment", which is plainly the position adopted by Dr Deleuil.)

31 The applicant's own doctor, Dr Greg Deleuil, had at the applicant's solicitor's request, undertaken an assessment of Mr Symons alleged degree of disability in accordance with chapter 5 of the USAMA Guide and, in doing so used the predicted values for the various indices for men set out in the tables in the USAMA Guide. On this basis Dr Deleuil concluded that the applicant's degree of disability varies across the spectrum of test results: on one reading (VO2 max) it showed that the patient falls into class 4 (on Table 8) and shows 51 per cent to 100 per cent severe impairment of the whole person. The other tests, FEV1 and DCO, show impairment between 10 per cent and 25 per cent but they fall closer to the more severe end of the disability scale within that class.

32 Dr Deleuil accompanied Mr Symons to his examination and assessment by the second Medical Panel and was involved in some dialogue with the members of the Panel during that process. In his affidavit sworn 29 October 2002 and filed in these proceedings, Dr Deleuil deposed that the members of the Medical Panel examined the report of the respiratory assessment which Dr Deleuil had himself prepared, as already described, and that one of the Panel members queried his source of the predicted levels applied in his assessment. Dr Deleuil explained that he had applied the predicted levels set out in chapter 5 of the USAMA Guide because he understood that they were the proper figures to be applied in assessing the level of lung function impairment. In response, the member of the Panel informed Dr Deleuil that the second Medical Panel, in considering Mr Symons' measured levels of lung function had decided that it was appropriate to apply the predicted levels of lung function employed by the Sir Charles Gairdner Hospital laboratory which carried out the respiratory function assessment ("non-prescribed background levels"). Dr Deleuil objected to this course, but there was no further discussion with the Panel members in this regard.

33 However, Dr Deleuil has since been shown, as a result of discovery in the present proceedings, a copy of his report of 19 March which can only be the copy which was handed to the members of the Medical Panel at the examination. This shows a number of manuscript alterations to Dr Deleuil's report by which the predicted values for FVC, FEV1 and DCO were all crossed out and substituted by lower values and that Dr Deleuil's ratios reached by application of the USAMA predicted values had been deleted. Dr Deleuil has confirmed that there were no such annotations on his report when it was submitted to the Panel and explains that this can only mean that the Panel has used predicted values other than those set out in the USAMA Guides. Dr Deleuil has deposed to his conclusion, which appears to be the only conclusion open in the circumstances, that the figure for disability derived by the second Medical Panel has resulted from a consideration of the applicant's respiratory function results as measured against non-prescribed background or predicted values.

34 Dr Deleuil's conclusion is consistent with the observation made to him by the member of the Medical Panel during the course of the examination. The same conclusion can be inferred from an examination of a report of the respiratory physician, Dr A W Musk AM, FRACP, FAFOM, dated 10 September 2002 which has been annexed to the applicant's affidavit in support of this present application. After the second Medical Panel made its determination, the solicitors for Mr Symons requested a further respiratory function test to be undertaken by Dr Musk and this was duly done at Sir Charles Gairdner Hospital on 26 August 2002. When reporting on the results of this test, indicating as it did a deterioration in Mr Symons' condition, Dr Musk addressed the methodology used and at the SCGH and its relationship to the USAMA Guide and said:

"The predicted levels of lung function used by the Pulmonary Physiology Department at Sir Charles Gairdner Hospital are:

FEV1 (Coates et al BMJ 1966; Volume 1; 1016-19) common vital capacity (Kory et al Com AM. Jnl J MED of 1961; Vol 30: 243-58) and gas transfer (Miller et al M.Rev Resp Dis 1983; Vol 127; 270-277). These are significantly different than those used in the AMA Guide (chapter 5) that you enclosed. This is because of the different population sample to represent 'normal' levels particularly for the FEV1/FVC since Coates included people who smoke.

As outlined in the results of our lung function assessment Mr Symons' forced vital capacity is 72% predicted, FEV1 is 78% of predicted and transfer factor is 68% of predicted. Using the predicted levels of the AMA his forced vital capacity is 65% of predicted, FEV1 is 65% of predicted and his transfer factor is 54% of predicted. Therefore according to the AMA Guidelines he is class 3: (moderate impairment of the whole person; Table 8: DLCO between 41% and 59% of predicted) although using the predicted levels of the Sir Charles Gairdner Hospital he is class 2 on all tests."

Plainly, it is not possible to use any of the results of an independent lung function test performed by Dr Musk in August 2002, after the examination by the second Medical Panel, in order to substitute more recent findings. Nevertheless, the explanation of Dr Musk serves to confirm that the use of the predicted levels of lung function employed by the Sir Charles Gairdner Hospital are significantly different than the USAMA Guide and, in this particular case, lead to lower determinations of disability.

35 The question, therefore, becomes whether the second Medical Panel in the present case has made a determination of Mr Symons' alleged lung disability in accordance with the Act and Regulations, that is in accordance with the USAMA Guide. It has been pointed out that the USAMA Guide includes a passage:

"Measurements of FVC and FEV1 should be compared to the values obtained from healthy subjects or reference values. Such values for both men and women are presented in Tables 2, 3, 5 (pp 156 through 159)"

and that the proper construction of this provision is that accepted reference values, may, in suitable cases, be substituted for reference values contained in the guide itself. Furthermore, as the submission goes, the USAMA Guide reveals that there are variations in standard levels for a population, as, for example between North American whites and North American blacks, and has acknowledged that there are, as yet unquantified, variations between Hispanics, Native Americans and Asians when compared with North American whites.

36 No doubt it is for reasons of this kind that the second Medical Panel employed reference values favoured by the Sir Charles Gairdner Hospital, presumably because it has been determined by experience that they correspond more closely with the average lung functions of healthy people in Western Australia. The issue, however, is whether or not this is a determination "in accordance with the Act and Regulations". I have come to the conclusion that it is not because despite a clear acknowledgement in the USAMA Guidelines that different predicted values for various types of lung function may be found in different categories of the US population, the methodology of quantitative assessment adopted by the American Guide is to make proportional adjustment for the quoted predicted values in the case of North American blacks but not in any other case. The quoted values, approximate although they may be for certain other classes of the US population, are nevertheless adopted and the quantitative method of assessment which has been adopted is based on the ratios determined from the use of those predicted values. Admittedly this may give some arbitrary results in individual cases and some unreliable results in others, but the purpose of the USAMA Guide is not to achieve precise mathematical accuracy nor diagnostic certainty but, rather, to provide guides to the degree of impairment.

37 The mathematical significance which is given to the degree of disability under s 93D of the Act is a characterisation which is determined by the policy underlining Pt IV Div 2 of the Act, namely, that persons with a disability less than that prescribed may not have access, or full access, to common law remedies for damages. No doubt the policy assumes, and expects, that in most cases it will be possible to make an accurate and objective assessment of the degree of physical disability for any individual, but it does not address the clinical uncertainties and limitations that are inevitable in certain methods of testing or evaluation such as have been identified in the present process. On the other hand, the statutory method has the virtue of objective, if occasionally arbitrary, mathematical determination but that carries with it, at least in my opinion, the obligation to follow without exception the methodology of assessment adopted by the legislature, despite the limitations or imperfections in that particular methodology. The methodology adopted is that contained in the USAMA Guide, whereas the methodology adopted by the second Medical Panel was a variation of that prescribed method with the use of different predicted values. While that may, perhaps, give a more accurate clinical result for individual cases in Western Australia, it is not the application of the USAMA Guideline and, in my opinion, is not a determination authorised by the Act or Regulations.

38 This is a conclusion which I reach without resort to principles of statutory interpretation which are often employed when construing the Workers' Compensation and Rehabilitation Act and other similar remedial legislation. However, resort to those principles can only reinforce the conclusion which I have reached.

39 In Bird v The Commonwealth [1988] HCA 23; (1988) 165 CLR 1 at 9, Deane and Gaudron JJ said:

"Moreover, it is well to remember that employee's compensation legislation, such as the Act and the Regulations, is remedial in its character 'and, like all such Acts, should be construed beneficially': Bist v London and South Western Railway Co [1907] AC 209 at 211. The 'established principle' was correctly identified by Fullagar J in the course of his dissenting judgment in Wilson v Wilson's Tile Works Pty Ltd (1960) 108 CLR 328 at 335 'where two constructions of a Workers' Compensation Act are possible that which is favourable to the worker should be preferred.' If a person or a case falls within the general spirit of such remedial legislation, and there are two possible interpretations, the courts ought not to construe the Act so as to exclude that person or case: cf Pearce, Statutory Interpretation in Australia 2nd edition (1981), pp 137-138."

Similarly, it is accepted that a court should favour an interpretation which restricts any extension to the modification of long-established common law rights, unless there is the clearest expression of parliamentary intention to do so - Bishop v Chung Bros [1907] HCA 23; (1907) 4 CLR 1262 at 1275, Hocking v Western Australian Bank (1909) 9 CLR 738 at 746; and Thompson v Mastertouch [No 3] TV Services Pty Ltd [1978] FCA 24; (1978) 38 FLR 397 per Deane J at 408.

40 While it is the case that the introduction of amendments to the Workers' Compensation and Rehabilitation Act to restrict, and in some cases remove, common law rights of action for damages introduce new objectives and policies into the Act, bearing upon the approach to its interpretation in cases of ambiguity: Kartinyeri v The Commonwealth [1998] HCA 22; (1998) 195 CLR 337 per Brennan CJ and McHugh J at 353 - 354 and Hewitt v Benale Pty Ltd [2002] WASCA 163, the present controversy does not involve any issue about the intended scope of the legislation introduced into Pt IV Div 2 by the 1993 amendments. The 1993 amendments make it clear that employees' former common law rights to sue for damages for alleged negligence or breach of duty causing personal injury in the course of his employment are to be excluded or diminished unless the worker establishes a degree of disability not less than the minimum prescribed. No encroachment on that legislative policy arises in the present case. Nor is there any encroachment upon the principle that the degree of disability of the worker must be no less than a degree determined in accordance with one of several methods of assessment prescribed by the legislation and the Regulations. Instead, the question is whether, under the Regulations, the prescribed method of assessment has been followed in this particular case.

41 In my opinion, if there had been any ambiguity in the meaning of the USAMA Guide in this context that would not be an ambiguity which could be resolved by a purposive construction to advance the objects of the Act. The objects are clear, and the methodology has been defined. It is simply a question, in this particular case, whether the application of that test has been correctly followed. Had there been any room for alternative views on that issue, I am satisfied that the conventional principles of statutory interpretation would result in the choice of an interpretation more favourable to the preservation of the worker's common law rights as claimed.

42 In the order nisi for certiorari the applicant also raises two other grounds for challenging the determination of disability of the second Medical Panel. The first ground involves an allegation of reasonable apprehension of bias because the chairman of the Panel was also chairman of the first Medical Panel whose decision had been quashed in the earlier proceedings - Northern Rivers FM Radio Ltd v Australian Broadcasting Tribunal & Anor [1990] FCA 229; (1990) 25 FCR 266 per Einfeld J at 267 - 273. Further, it was submitted that in failing to give reasons for its decision the Medical Panel failed to afford procedural fairness or that this constitutes an error of law. In the present case there is no express statutory obligation on the Medical Panel to give reasons on the present application, as distinct from an obligation under s 145A for a Medical Assessment Panel to give reasons.

43 The rules dealing with alleged bias or a reasonable perception of bias have recently been fully considered by the High Court in Ebner v Official Trustee in Bankruptcy [2000] HCA 63; (2000) 205 CLR 337. In that case Gleeson CJ, McHugh, Gummow and Hayne JJ observed (at 344) that a judge is disqualified if a fair-minded lay observer might reasonably apprehend that the judge might not bring an impartial mind to the resolution of the question the judge is required to decide: R v Watson; Ex parte Armstrong [1976] HCA 39; (1976) 136 CLR 248; Livesy v NSW Bar Association [1983] HCA 17; (1983) 151 CLR 288; Vakauta v Kelly [1989] HCA 44; (1989) 167 CLR 568 and Johnson v Johnson [2000] HCA 48; (2000) 201 CLR 488. The question of whether or not a decision of a tribunal should be quashed on the grounds of reasonable apprehension of bias on the grounds that one or more of its members, participated in an earlier hearing and reached a decision in the same matter which was later overturned or quashed was reviewed extensively in the decision of the Full Court in Julien v Racing Penalties Appeal Tribunal of Western Australia [2001] WASCA 345 and the authorities are collected in [59]. It was also said in Minister for Immigration & Multicultural Affairs v Wang (2003) 77 ALJR 786 per Gleeson J at 790 - 791 that justice requires that a tribunal undertaking a determination of a statutory question should consider the claim fairly and on its substantial merits. In such cases fairness may require that, in a given case, the applicant be protected against the possibility, or the appearance, of adverse pre-judgment but that it does not require protection against the risk that an open-minded judgment will result in a view of certain facts less favourable than that of an earlier decision-maker whose decision has been set aside completely.

44 In the present case I do not see any basis upon which it could be concluded that there was a reasonable apprehension that the chairman of the second Panel might be regarded by fair-minded observers as possibly being biased against the applicant, simply because of his involvement in the determination of the first Medical Panel's assessment. As has been described, in the absence of a prescribed method for determining disability in the case of respiratory disability, the first Medical Panel embarked on a clinical method of assessment which it can only have chosen for itself as an appropriate diagnostic method. That this method was not approved by the Act or Regulations, which failed to address this situation at all, does not reflect in any way against the members of the first Medical Panel, nor, in my view, can it give rise to any reasonable apprehension that, since the amendment to the Workers' Compensation Regulations in 2002 which introduced the methodology contained in the USAMA Guide, could it suggest that there was any disinclination by the chairman or any other member of the second Panel to follow the method prescribed by the USAMA Guide. That, in applying the American Guide, the second Medical Panel has chosen to adopt predicted normal respiratory values for men in Western Australia as used by SCGH, even if wrong as I have held it to be, is no indication of bias either but, rather, an understandable desire to obtain the most scientifically acceptable conclusion rather than to follow, unswervingly, the USAMA Guide, prepared as that was for a different population base. Accordingly, the submission that the decision of the second Medical Panel should be quashed on the grounds of reasonable perception of bias is rejected.

45 On the first successful application for certiorari: Re Medical Panel; Ex parte Symons [2001] WASCA 280, the decision of the Panel was also challenged on the grounds that the Panel should have, but did not, provide reasons for its decision. However, as a right to certiorari was made out on other grounds, the Full Court considered that it was unnecessary to determine whether or not there was an obligation by a Medical Panel to give reasons in this case and, if so, whether a failure to do so rendered the decision liable to be quashed. The same situation arises again because I have already concluded that there was an error by the second Medical Panel and because I am satisfied that for this reason alone its determination should be quashed. This makes it unnecessary for me to deal with the question of the alleged obligation of the Medical Panel to give reasons but, as this was expressly raised by the order nisi and was fully argued before me, and also because it is likely that a further determination according to law will be required of a Medical Panel, it is desirable that I address this point.

46 There is a distinction between the abilities and function of a Medical Panel to whom a question is referred under s 36 of the Act and that of a Medical Assessment Panel to whom a question is referred for determination under s 145A. A Medical Assessment Panel does not have the jurisdiction to deal with a question that is within the jurisdiction of a Medical Panel established under s 36 - see s 145. The determination of a Medical Assessment Panel under Pt VII must be given with reasons and within a limited time - s 145E(4). By s 93E(11) any dispute relating to the disability mentioned in s 33, s 34 or s 35 (including in this case disability due to lung cancer (s 33(c)) is to be referred to a Medical Panel for determination as described in s 36, except that the only question to be considered and determined on the reference is the question that was referred. The determination by any such Medical Panel is final and conclusive and binding on the worker, on his employer, and on any tribunal in which such determination is relevant - s 38(4).

47 However, unlike s 145E(3) relating to the determinations of Medical Assessment Panels, there is no obligation on a Medical Panel appointed under s 36 in express terms to provide reasons for its determination. The absence of such a provision, especially in contrast with the provisions of s 145E(3), led the amicus curiae to submit that there is consequently no obligation for a Medical Panel under s 36 to give reasons for its decision and, indeed, that the statutory implication is to the contrary. Furthermore, the amicus curiae relied heavily on the decision of the High Court in Public Service Board of NSW v Osmond (1986) 159 CLR 656 which has established that there is no general rule of the common law or principle of natural justice which requires reasons to be given for administrative decisions, even those made in the exercise of a statutory discretion and liable adversely to affect the interests, or to defeat the legitimate or reasonable expectations, of others. The rule in Osmond's case has been subject to much subsequent critical and academic analysis and review and judicial discussion. Some of the authorities reviewing the issue are cited by Fitzgerald P in his dissenting judgment in Cypressvale Pty Ltd v Fernmead Pty Ltd & Anor, unreported; Court of Appeal Queensland; 158 of 1994; 19 May 1995 at p 14 and 15, but the rule stands. Osmond's case, of course, dealt with an appeal by an unsuccessful applicant for a public service position to the Public Services Appeal Board and plainly involved a discretionary administrative decision, because the applicant had no legal or other right to be appointed to the desired position.

48 Whatever may be the distinctions between a determination made by a Medical Assessment Panel under s 145E(3) and a determination made by a Medical Panel under s 38 on a referral by the Director under s 93E(11), it cannot be that one is a discretionary administrative decision and the other is not. In each case, the Medical Assessment Panel or the Medical Panel is required to make an objective determination upon the evidence presented to it and the special skill, knowledge and expertise possessed by the members of that Panel as a result of their own qualifications and specialisation, to answer a question of fact about the extent of an alleged disability. Neither Panel has a discretion to decline to answer the question or questions referred, so far as they are capable of being answered, nor does it have a discretion to substitute or answer some other question or questions. The consequence of a determination of the Medical Panel under s 38(4) is that it is final and conclusive and binding on the worker and his employer and on any tribunal in which such determination is relevant. In the absence of a material change in his circumstances this will prevent the worker or his employer from asserting or contending for a different level of disability in any other proceedings: Waddington v Silver Chain Association [1998] WASCA 331; (1998) 20 WAR 269; Kuligowski v Metrobus [2002] WASCA 170; (2002) 26 WAR 137 and United Construction Pty Ltd v Maketic [2003] WASCA 138.

49 For the purposes of Pt IV Div 2 of the Act, and particularly s 93C, s 93E(3) and s 93F this determination directly affects, and may deny or restrict, the worker's former common law right to bring an action for damages for alleged negligence or breach of duty against his employer or any other person for whom the employer is vicariously liable. Accordingly, it can be seen that the determination of a Medical Panel has a direct effect upon a worker's common law rights and, for that reason, should not, in my view, be described as an administrative decision. The decision may not be a decision of a court but the members of the Panel have a duty to act judicially in that their decision must be made according to law, on the basis of evidence before them including the results of their own clinical examination, and with regard to objective specified criteria established by the Act or Regulations. That certiorari will lie at all to such a Panel, as has been established in Re McWilliam; Ex parte Juras, unreported; SCt of WA; Library No 960637; 11 October 1996; Re Gillett; Ex parte Rusich [2001] WASCA 111 and Re Medical Panel; Ex parte Symons [2001] WASCA 280 also reveals that the Panel has a duty to act judicially. Consequently, in my view, the question of whether or not the Tribunal was obliged to give reasons for its determination cannot be answered by recourse to the decision of the Public Service Board of NSW v Osmond (supra), but, rather, must be gleaned from the Act and the character which a determination by such a Medical Panel bears.

50 The question of the sufficiency of reasons given by a Medical Assessment Panel, which has a statutory obligation to give reasons under s 145E of the Act, was fully reviewed recently by the Full Court in Re Croser; Ex parte Rutherford [2001] WASCA 422; (2001) 25 WAR 170, where an order nisi for certiorari was made absolute quashing the whole determination of the Panel because of inadequacy of reasons provided. It was said in that case by Olsson AUJ, with whom Steytler J agreed and where, on this point, Murray J also appears to have agreed, that:

"It is certainly clear that, if a failure to give adequate reasons gives rise to an inference that a tribunal has failed to exercise its powers according to law, then an appellate court will be justified in interfering: see Repatriation Commission v O'Brien (1985) 159 CLR 422 at 446 ... The essential requirement for the giving of adequate reasons is that they disclose the reasoning processes of the relevant tribunal. This, in turn, should enable the parties and, for that matter, any court of review to determine whether there has been a reviewable error.

Although there has, over time, been some judicial difference of opinion on the point, there is now firm authority for the proposition that the failure of a judicial officer to give adequate reasons for decision will normally constitute an error of law: see Pettitt v Dunkley [1971] 1 NSWLR 376; Fleming v The Queen [1998] HCA 68; (1998) 197 CLR 250 at 260 [22]; Papps v Police [2000] SASC 183; (2000) 77 SASR 210. The rationale for that conclusion is that, where inadequate reasons are given, the function which the law calls upon the judicial officer to exercise has not properly been fulfilled: see also the discussion of the relevant authorities by Doyle CJ in R v Keyte [2000] SASC 382; (2000) 78 SASR 68 at 77 - 79."

51 The rationale for giving reasons for decision has been stated in several ways and on many occasions with emphasis upon the necessity for reasons for decision to give efficacy to any right of appeal which may be conferred by the relevant legislation. That rationale also has force if there are other avenues of review such as, in this case, judicial review by certiorari, although because of limits on the scope of the permitted review, and the scope and adequacy of the reasons, may for that reason be somewhat different. However, perhaps the most fundamental explanation for the necessity for reasons for decision is that provided by Asprey JA in Pettitt v Dunkley [1971] 1 NSWLR 376 at 382:

"Findings of fact and ... reasons are essential for the purpose of enabling a proper understanding of the basis upon which the verdict entered has been reached and the Judge has a duty, as part of the exercise of his judicial office, to state the findings in the reasons for his decision adequately for that purpose. If he decides in such a case not to do so, he has made an error in that he has not properly fulfilled the function which the law calls upon him as a judicial person to exercise and such a decision on his part constitutes an error of law."

52 That passage has expressly been cited with approval by Doyle CJ in R v Keyte [2000] SASC 382; (2000) 78 SASR 68. Pettitt v Dunkley was cited with approval in Fleming v The Queen [1998] HCA 68; (1998) 197 CLR 250 at 260 in terms, by Gleeson CJ, McHugh, Gummow, Kirby and Callinan JJ which expressly stated that their Honours should not be taken as acceding to the view that new ground was broken in that decision.

53 Against these considerations, there does not seem to be any countervailing reason why some succinct reasons by a Medical Panel should not be given when making a determination under s 38, especially, whereas in this case, on both times when determinations of the Medical Panel have come up for review before this Court on applications for certiorari, it is apparent that difficult questions of law can arise for determination by the Medical Panel and errors can be made which may lead to injustice. Obviously, for a Panel comprised of medical practitioners, without legal qualifications or experience, one should not expect comprehensive sets of reasons for decision such as would be given by a Judge at the end of a trial of a contested civil case. The question of the adequacy of reasons for decision is, however, quite a different matter and one upon which there is an ample jurisprudence in existence, as exemplified by Re Croser; Ex parte Rutherford (supra).

54 Returning to the basic question of whether or not a Medical Panel should give reasons for its determination of the level, if any, of disability found on the reference made to it, it appears to me that all the factors which have led to the law concluding that a judicial officer normally has, as an incident of his office, a duty to give reasons for any decision on a matter determined by him, favour the conclusion that there is a similar obligation resting upon a Medical Panel. The determination which is final and binding upon the worker and his employer will directly affect their mutual legal rights and obligations. It is a finding of fact which must be based on evidence put before the Panel and upon the Panel's own expert assessment of the subject. It is also a determination which must be made with regard to fixed and objective criteria specified by law. There is no scope for any discretionary component in the determination nor for any discretionary refusal to make a determination.

55 The absence of an express statutory obligation to provide reasons for decision by a Medical Panel under s 38 does not to me convey an implication that reasons for the determination cannot, should not or need not be given. Nor is there, or could there be, any particular form prescribed by the Act for the determination by a Medical Panel reporting upon its examination of the subject. It is to be noted that a standard pro forma form of report has been used by both Medical Panels for the examinations of the applicant, Mr Symons, but the detail of the determination and the explanation of it appears to me to be matters which should be decided upon by the Medical Panel itself rather than be suggested or circumscribed by any particular form, the use of which may, for any reason, have been prevalent. What seems to be required is a determination by the particular Medical Panel identifying the materials submitted to it, stating whether or not an examination of the subject was conducted and, if so, what were the material findings including relevant parts of any history given by the subject and, in the light of those findings what, if any, quantitative finding of disability was made by the Medical Panel. This should be done with sufficient details of the methodology or calculations to render the conclusion comprehensible in the light of the basic data and the test for particular disability prescribed by the Act or the Regulations. In the absence of such reasons a determination may prove to be inscrutable and therefore prone to the conclusion that the function which the law calls for the Medical Panel to exercise has not properly been fulfilled - see Re Croser; Ex parte Rutherford (supra) at [67].

56 It certainly cannot be said that a determination by a Medical Panel on a referral under s 93E(11) is interlocutory or procedural in character, and thus of limited or temporary significance or that it is part of a regime for the determination of facts or rights which has been placed beyond any form of judicial review by some form of legislative privative clause more extensive than s 38(4). There has been no exclusion of certiorari as an avenue for judicial review of a determination of a Medical Panel. Such a determination should not be incapable of review merely because the determination, in its terms, does not reveal whether or not the correct statutory test has been applied. This also provides another reason for rejecting the submission that the absence of an express statutory obligation for a Medical Panel to give reasons constitutes a negative implication against the existence of any such obligation at all.

57 Accordingly, I conclude that a Medical Panel undertaking a determination of the extent, if any, of a disability on a dispute referred to it by the Director under s 96E(11), when making its determination under s 38 should provide reasons which reveal the steps taken by the Panel, and the tests applied, in making that quantitative determination. This was not done in the present case, indeed the Medical Panel, on what appears to be standard advice relying, inappropriately, on the decision in Public Service Board v Osmond (supra) refused to provide any written reasons and asserted that it was under no obligation to do so. The letter dated 23 April 2002 provided by the Industrial Diseases Medical Panel (Annexure EJS 12 to the affidavit of the applicant sworn 17 September 2002), nevertheless asserted that "on the day the Panel convened, the parties present, including Mr Symons, were verbally advised of the basis of the determination" which I take to be confirmation of the evidence of Dr Deleuil that the Medical Panel used the reference or predicted normal values for respiratory function utilised by the SCGH Pulmonary Physiology Department, rather than the predicted reference values cited in the USAMA Guide. There has certainly been no submission in these proceedings that the Panel was acting ultra vires in providing this limited oral explanation for its determination during the course of its proceedings, nor any submission that this was not an indication of its reasons for the determination made.

58 I am satisfied that a writ of certiorari should issue to quash the second determination of the Medical Panel in this case and, accordingly, there will be an order absolute made. This will mean that the dispute previously referred to the Medical Panel in this case by the Director has still not been determined and it will therefore be necessary for a Medical Panel to undertake such a determination, in conformity with the requirements of the Act and the Regulations as determined by this decision. Whether this requires any further examination of the appellant, accompanied by his own medical practitioner should he wish, before the Medical Panel, or whether the determination can be carried out by applying the USAMA Guide predicted normal readings for respiratory function contained in chapter 5 of the Guide, to the personal findings of the applicant obtained at the examination conducted by the Medical Panel on 20 March 2002 are matters which I consider the Medical Panel itself should determine as part of its responsibility for performing its function of conducting an adequate examination and determination under s 38. In either case, reasons for the eventual determination should be given by the Medical Panel.