Repatriation Commission v O'Brien

[1985] HCA 10

HIGH COURT OF AUSTRALIA

Gibbs C.J., Murphy, Wilson, Brennan and Dawson JJ.

THE REPATRIATION COMMISSION v. JOHN DAVID O'BRIEN

(1985) 155 CLR 422

27 February 1985

Repatriation Pension

Repatriation Pension—Incapacity arising out of or attributable to war service—Connexion between physical condition and war service—Administrative Appeals Tribunal—Jurisdiction—Satisfaction beyond reasonable doubt that grounds insufficient to grant claim—Repatriation Act 1920 (Cth), ss. 24AA, 47, 101, 107VZZB—Administrative Appeals Tribunal Act 1975 (Cth), ss. 25, 43, 44(1).

Decisions

GIBBS C.J., WILSON and DAWSON JJ. The respondent served in the Royal Australian Air Force from 20 January 1942 to 1 July 1946. He did not serve in a theatre of war, his service being wholly confined to Australia. On 12 July 1946, a Repatriation Board, constituted pursuant to the Repatriation Act 1920 (Cth), as amended, ("the Act"), accepted a claimed incapacity for right sesamoiditis hallux as due to war service. On 3 August 1954 a Repatriation Board accepted a claimed incapacity arising from duodenal ulcer and fibrositis as being due to war service. In 1961 anxiety hysteria was diagnosed and, on 9 November 1961, a Repatriation Board accepted the neurosis as due to war service but assessed the incapacity as negligible. On 31 August 1970, a claim in respect of a hiatus hernia was accepted. Apart from these claims, a number of other claims were made over the years and were rejected. He was frequently in receipt of treatment for stomach and back troubles. In 1970, the assessment of his disability in respect of anxiety hysteria was raised from nil to 20%. Finally, in October 1974, the respondent sought a war pension because of a recently diagnosed condition of essential hypertension which he claimed was related to his accepted disability of anxiety hysteria. A Repatriation Board rejected the claim in August 1975. In the following four and a half years the claim was considered on no less than five different occasions by the Repatriation Commission ("the Commission"). On each of those occasions the Commission considered the case on the basis of the evidence then before it and on each occasion it rejected the respondent's appeal. So far as the first four occasions on which the matter was before the Commission are concerned, each successive decision was appealed to the War Pensions Entitlement Appeal Tribunal, the case being returned to the Commission on each of those occasions for reconsideration in the light of further evidence tendered on behalf of the respondent. The decision of the Commission on the fifth occasion was the subject of an appeal by the respondent to the Appeal Tribunal but before the proceedings in that Tribunal were finalized the Repatriation Acts Amendment Act (No. 18 of 1979) operated to replace that Tribunal with the Repatriation Review Tribunal ("the Review Tribunal"). The Review Tribunal then proceeded to hear the respondent's appeal as if it were an application for review made to the Review Tribunal pursuant to s. 107VC of the Act. During the hearing, the procedures contemplated by s. 107VZZB of the Act were put in train, the end result of which was a direction by the President of the Administrative Appeals Tribunal ("the AAT") in accordance with s. 107VZZB(8) that the AAT review the five decisions of the Commission. On 15 March 1983, the AAT delivered its decision affirming the decision of the Commission to disallow the respondent's claim. Pursuant to s. 44 of the Administrative Appeals Tribunal Act 1975, he appealed from that decision to the Full Court of the Federal Court of Australia (Sweeney, Keely and Fitzgerald JJ.) which unanimously set aside the decision of the AAT and granted the claim. Thereafter this Court gave special leave for the present appeal to be brought.

2. The hearing before the AAT produced a major battle of the medical experts. In addition to many reports and opinions in writing, no less than eight medical practitioners were examined and cross-examined on their written opinions. There were two basic questions put in issue by the parties. The first was whether an admitted condition of the applicant described as anxiety neurosis or anxiety hysteria had arisen out of or was attributable to his war service. The second was as to the connexion, if any, between that anxiety state and the essential hypertension the subject of the claim. Five of the medical witnesses were called by the respondent and their evidence, if accepted, would have established both issues in the respondent's favour. However, the other medical witnesses called by the Commission expressed quite different opinions. In a lengthy judgment, the AAT examined the medical evidence in detail and then made findings as follows:

"1. The applicant between 20 January 1942 and 1 July 1946, both dates inclusive, was a member of the Forces on war service. 2. The applicant experienced a period of suppressed hostility before and after the period of his war service induced by circumstances at his work. 3. Applicant developed during or after his period of war service an anxiety neurosis. 4. The cause of this anxiety state was some or all of the following, viz., having a wife with a young child, then having a wife who became pregnant in what were said to have been unfavourable living conditions; having a wife who depended a lot on him; having a wife who was unable to obtain suitable support systems for herself within the community or reasonable accommodation; having a wife who was threatening a jump over the Gap; having a wife who was experiencing stress and he was removed from it; then having a will to go overseas and living in the land (bind?) of his wife wanting him near her; preoccupation with what he conceived to be the attitude of his colleagues at work; and with the question of overseas service. 5.If the applicant developed or there was aggravated an existing condition of anxiety state during or after the period of his war service, it did not arise out of nor was it aggravated by nor attributable to his war service within the meaning of that expression in the Act s. 100. 6. On 12 December 1974 the applicant was diagnosed as having hypertension. 7.The applicant's hypertension arose out of or was developed by reason of constitutional factors. 8. Any stress which may have aggravated the applicant's anxiety neurosis or aggravated or contributed to the development of his condition of hypertension did not arise out of nor was it attributable to his said war service. 9. The applicant's incapacity from his condition of essential hypertension did not arise, was not attributable to and was not aggravated or accelerated his war service."

The AAT then proceeded at once to state its conclusion:

"On a consideration of all evidence and submissions, we are satisfied beyond reasonable doubt that there are insufficient grounds for granting the claim or application of the applicant."

3. The learned Solicitor-General for the Commonwealth, appearing on behalf of the Commission, argues that the Federal Court should not have set aside the decision of the AAT. He submits that the AAT was entitled to choose between the conflicting medical testimony and to make the findings which it did even though those findings involved the outright rejection of the opinion of some of the medical experts. As a general statement of the role of a fact-finding tribunal, the submission is of course clearly correct. But in its application to a case requiring the determination pursuant to the Act of the entitlement of an ex-serviceman to a pension the heavy burden of proof placed on the Commission by the provisions of the Act to which reference will be made in this judgment must always be borne in mind. The distinction is emphasized by Aickin J. (with whose judgment Gibbs C.J., Stephen and Mason JJ. concurred) in Repatriation Commission v. Law (1981) 147 C.L.R. 635, at p. 651:

"In a civil court it would be necessary for the judge, or the jury if there were one, to hear oral evidence from the expert witnesses and to resolve any conflict on the balance of probabilities, taking into account the impression given by each expert witness. The Review Tribunal in the present case was in a very different position. In the first place it had only the written reports of the expert witnesses. Moreover it was required to find in favour of the applicant unless it was satisfied beyond reasonable doubt that there were insufficient grounds for doing so. Thus a heavy onus was placed upon the Commission to satisfy the Tribunal beyond reasonable doubt of that negative proposition. Although the medical reports were in conflict, no challenge appears to have been made to the standing or expertise of any of the medical experts. In that situation it is difficult indeed to see how the Tribunal could properly have been satisfied beyond reasonable doubt that the reports favourable to the applicant were wrong."

In Law, apparently, the Tribunal was prepared to find the facts on the basis of medical reports. In the present case, many of the experts were called as witnesses and subjected to rigorous cross-examination. When evaluating the evidence, the AAT was entitled to put aside evidence of medical opinion supporting a connection between the disability which was the subject of the claim and the claimant's war service if, but only if, it was satisfied beyond reasonable doubt that such evidence should not be accepted. As will appear, it is unnecessary for us to examine the judgment of the AAT in detail in order to determine whether it reflects the proper approach in this regard.

4. We have explained that the first of two basic questions put in issue by the parties in the AAT hearing was whether the respondent's anxiety neurosis had arisen out of or was attributable to his war service. The fifth finding of the AAT determined this question in favour of the Commission. With all respect and despite the valiant advocacy of the Solicitor-General, we consider it to be a surprising conclusion. In our opinion, it flies in the face of commonsense to say that an anxiety neurosis which is occasioned by reason of the separation of the respondent from his wife because of his war service at a time when she is in desperate need of his company is not attributable to that war service. It is even more surprising when tested by the onus of proof provision.

5. But in any event, Mr. Grieve, counsel for the respondent, takes a more substantial objection to this finding. In his submission, the question of a connexion between the respondent's anxiety neurosis and his war service fell outside the terms of the reference to the AAT and should not have been entertained by it at all. The provisions of s. 107VZZB of the Act outline with some precision the circumstances in which a decision of the Commission under review by the Review Tribunal may be referred by the President of that Tribunal to the President of the AAT with a request for a review of that decision by the AAT. Subsection (8) of the section obliges the President of the AAT, upon receipt of such a request, to direct the review, in accordance with the Administrative Appeals Tribunal Act, of the decision which has been referred to him.

6. In the present case, the reference was confined to the five decisions of the Commission whereby on each occasion the respondent's claim for a war pension based on his essential hypertension was rejected. The decision of a Repatriation Board in November 1961 accepting the respondent's anxiety neurosis as due to war service has never been challenged by way of appeal. The same is true of the decision of a Board in 1970 which raised the assessment of his disability in respect of that neurosis from nil to 20%. Whether or not the Commission considered it desirable to do so, in our opinion it was not open for these earlier decisions to be reviewed and reversed in the course of considering the respondent's claim based on his hypertension. Neither of these earlier decisions were embraced within the reference to the President of the AAT. The AAT therefore had no jurisdiction to review either of those decisions: Administrative Appeals Tribunal Act, s. 25.

7. We are confirmed in our acceptance of Mr. Grieve's submission by the fact that the Commission makes no response to it by way of reply. Further confirmation is to be found in the statement made by the President of the Review Tribunal when referring the matter to the President of the AAT, a statement which he is obliged to make by s. 107VZZB(7). A paragraph of that statement reads as follows:

"The first important principle of general application that arises in this case is whether, on the medical evidence available in this case concerning the relationship between the Applicant's accepted disability of anxiety hysteria and the subsequent development of hypertension, the Repatriation Commission, on a review of the case where these elements are present, can be satisfied beyond reasonable doubt that there are insufficient grounds for granting the application." (our emphasis).

It follows that the first of the two basic issues which the parties chose to contest in the AAT was misconceived. It was an issue which the AAT had no power to entertain. The real issue was the connexion, if any, between the accepted disability of anxiety neurosis and the essential hypertension. It was not suggested by the respondent that there was any other basis on which he could claim his hypertension was attributable to his war service.

8. This misunderstanding of the matter in issue goes far to undermine the acceptability of the AAT's ultimate decision. If the AAT had accepted, as it was in law obliged to do, that the respondent's anxiety neurosis was attributable to or aggravated by his war service, it would then have been obliged to concentrate its attention on the question of a connexion between that neurosis and the hypertension. As it was, having dismissed any relevant relation between the neurosis and his war service, the possibility of a connexion between the neurosis and the hypertension became of no importance as a factor supporting the claim for a pension. Although the AAT found that the respondent's hypertension arose out of or was developed by reason of constitutional factors, it went on to make its eighth finding as follows:

"8. Any stress which may have aggravated the applicant's anxiety neurosis or aggravated or contributed to the development of his condition of hypertension did not arise out of nor was it attributable to his said war service".

In our opinion, this finding should be taken as allowing for the possibility that stress associated with the respondent's anxiety neurosis may have been a factor in the development of his hypertension. That being the case, it follows that, had the AAT properly instructed itself with respect to the status of the anxiety neurosis as an accepted disability, it could not have been satisfied beyond reasonable doubt that there were insufficient grounds for granting the claim.

9. It is argued for the Commission that, in the event of the AAT being found to have been in error in making findings with respect to the conflicting medical testimony, the Federal Court should have sent the matter back to the AAT. It is true that an appeal from the AAT to the Federal Court is limited to questions of law (s. 44(1), Administrative Appeals Tribunal Act, 1975) and that in such a case the appellate body should not usurp the fact-finding function of the AAT. However, in view of the eighth finding and having regard to the medical evidence as a whole interpreted in the light of the comments of the AAT upon the witnesses, we have no hesitation in holding that a conclusion adverse to the respondent could not reasonably be entertained. The appeal therefore should be dismissed. It is with a sense of relief that we arrive at a decision which enables this long series of hearings to come to an end.

10. If the matters which we have discussed were the only matters which have been agitated in this appeal, one might legitimately wonder what it was that justified the grant of special leave to this Court. However, in addition to his attack on the legal merits of the case, the Solicitor- General urged the Court to examine and determine the correctness or otherwise of a general discussion in the joint judgment of Keely and Fitzgerald JJ. of questions of evidence and proof under the Act. That discussion was undertaken by their Honours at the invitation of the Commission "to remove the confusion". It is the Commission's present contention that the views expressed in the joint judgment are erroneous.

11. After an exhaustive examination of the decision of this Court in Law, and of the decision of the Full Court of the Federal Court in the same case (1980) 31 A.L.R. 140 and a number of cases decided subsequently by the Federal Court including Repatriation Commission v. Byrne (1981) 40 A.L.R. 296, Lennell v. Repatriation Commission (unreported, Federal Court of Australia (Full Court), 3 February 1982), Rose v. Repatriation Commission (1982) 44 A.L.R. 504, Repatriation Commission v. Bishop (1983) 48 A.L.R. 461 and Repatriation Commission v. Compton (1984) 53 A.L.R. 115, their Honours expressed their conclusion as follows:

"If there is material which tends to disprove a fact, the question arises whether the non-existence of that fact is the only rational conclusion on all the material, including such material, if any, as points to the possibility that the fact does exist. A 'real' possibility of the existence of that fact may be founded on something in the material which points to its existence or may arise from a lack of sufficient cogency in the material to disprove its existence or from some deficiency in the range of that material. A real possibility of the existence of a fact may be left open by material although there is nothing in the material which points to that possibility. The possibility may in such circumstances be 'speculative' but it is nonetheless 'real', not 'fanciful', in the relevant sense, for the very reason that, on the evidence, the non-existence of the fact is not the only rational conclusion. If there is no material in respect of a fact, or if the material is neutral in the sense that it leaves the existence of the fact unknown, there is no rational basis for a choice between the conclusion that the fact does exist and the conclusion that it does not. The non-existence of that fact is not the only rational conclusion. There is no need that there also be material which points to a 'real' possibility of the existence of that fact. That 'real' possibility is left open by the evidence.

Thus, it may not be established beyond reasonable doubt that incapacity or death is not 'connected with' war service either because there is material which points positively to a cause of the incapacity or death which is or might be so 'connected' ..., or because of some inadequacy in the material to show the absence of a connection".

12. The Commission challenges this exposition. It argues that if there is no evidence accepted by the Tribunal that a claimant's incapacity arose out of or is attributable to his war service, it must follow that the Tribunal will be satisfied beyond reasonable doubt that there are insufficient grounds to grant the claim. These grounds will be insufficient if there is nothing in the material accepted by the Tribunal that points positively to a real possibility of the requisite connexion between incapacity and war service.

13. As we have shown, it is not necessary for the purposes of the present case to choose between these rival contentions and we hold grave doubts as to the wisdom of embarking on an academic discussion divorced from the circumstances of a particular case. However, there may be something to be said for a brief examination if the clarification thereby attempted helps to slow the extraordinary flow of appeals to the Federal Court that has been evident in recent years.

14. It will be remembered that the material provisions of the Act are the following:

"101. (1) Upon the incapacity or death - (a) . . .; or (b) of any member of the Forces whose incapacity or death has arisen out of or is attributable to his war service,

the Commonwealth shall, subject to this Act, be liable to pay to the member, or his dependants, or both, as the case may be, pensions in accordance with Division 1: ...". "24AA. (1) A claim for pension - (a) shall be in accordance with the approved form; and (b) shall be accompanied by such evidence available to the claimant as he considers may support the claim. (2) Sub-section (1) shall not be taken as imposing any onus of proof on a claimant."

Section 24AB obliges the Secretary of the Department to cause an investigation to be made into the matters to which the claim relates. When that investigation is concluded, the claim together with the evidence furnished by the claimant, the relevant departmental records and a report of the results of the investigation must be submitted to a Repatriation Board or to the Commission as the case may be for determination whether the incapacity arose out of or is attributable to his war service (s. 27(1)). An appeal lies to the Commission from any determination by a Board (s. 28). Section 47 provides:

"(1) The Commission, or a Board, in hearing, considering, determining or deciding a claim or application, and the Commission, in hearing, considering or deciding an appeal - (a) is not bound by technicalities, legal forms or rules of evidence; and
(b) shall act according to substantial justice and the merits and all the circumstances of the case, and, without limiting the generality of the foregoing, shall take into account any difficulties that, for any reason, lie in the way of ascertaining the existence of any fact, matter, cause or circumstance, including any reason attributable to - (i) the effects of the passage of time, including the effect of the passage of time on the availability of witnesses; or (ii) an absence of, or a deficiency in, relevant official records, including an absence or deficiency resulting from the fact that an occurrence that happened during the service of a member of the Forces was not reported to the appropriate authorities.

(2) The Commission or a Board shall grant a claim or application, and the Commission shall allow an appeal, unless it is satisfied, beyond reasonable doubt, that there are insufficient grounds for granting the claim or application or allowing the appeal, as the case may be."

15. It will be observed that the provisions of s. 47 govern the hearing by the Commission of an appeal from a determination by a Repatriation Board. They correspond substantially to the provisions of ss. 107VG and 107VH of the Act, which apply to a review undertaken by the Review Tribunal. In the present case, both the AAT and the Federal Court were mistaken in their references to s. 107VH as a relevant provision. The reference should have been to s. 47. Section 43 of the Administrative Appeals Tribunal Act provides that for the purpose of reviewing a decision, the Tribunal may exercise all the powers and discretions that are conferred by any relevant enactment on the person who made the decision. The decisions which were under review in the present case were made by the Commission, not the Review Tribunal. However, the error is of no consequence.

16. We are not persuaded that the Commission's contention on the application of s. 47(2) of the Act is correct. The following considerations must be borne in mind:

(a) there is no onus of proof of a claim placed on a claimant (see s. 24AA(2)); (b) no matter how diligent the Department may be in its investigation of the claim, there is no guarantee that it will discover all relevant facts; (c) the Commission, in considering an appeal, must take into account the various matters set out in s. 47(1)(b); and (d) a claim must be granted unless the Commission "is satisfied, beyond reasonable doubt, that there are insufficient grounds for granting the claim" (see s. 47(2)).

When regard is had to these considerations, it seems to us to be impossible to lay down the law by saying that if the material in a particular case does not provide some positive inference in favour of the requisite connexion between death or incapacity and war service then the Commission or Review Tribunal as the case may be must be satisfied beyond reasonable doubt that there are insufficient grounds to grant the claim. To require the material to satisfy any prescribed test expressed in positive terms in favour of granting a claim tends to undermine the "heavy burden of disproof" (per Toohey J. in Law, (1980) 29 A.L.R. 64, at p. 74, citing Edmund Davies J. in Coe v. Minister of Pensions and National Insurance (1967) 1 Q.B. 238, at p. 242). Of course, it will be seldom that the evidence will be left in such an unsatisfactory state as to fail to yield some indication of the strength or otherwise of a connexion between the death or incapacity and the war service. That indication will ordinarily be supplied by evidence as to the cause of the death or incapacity, including the nature of any relevant disease and the circumstances which may give rise to it, all of which may then be examined in the context of the history of the member's war service. But where the accepted material falls short of addressing any or all of those questions - indeed, whatever the state of the evidence may be - at the end of the day there is only one question for the determining body to answer: is it satisfied, beyond reasonable doubt, that there are insufficient grounds for granting the claim? That is the test for which the Act provides and we do not think it is helpful to attempt to clarify it or improve upon it by suggesting another form of words to express its meaning and effect. Any such attempt is more likely to mislead.

17. In our opinion, the exposition contained in the joint judgment (and of which we have cited only the essence) should be accepted as reflecting a proper understanding of the legislative intent with respect to the granting of pension claims under the Act. It is unnecessary to recapitulate that exposition in detail. Two matters should however be made clear. The first is that although their Honours spoke of the disproof of a fact, s.47(2) does not require the Tribunal to grant a claim unless it is satisfied beyond reasonable doubt of the non-existence of every evidentiary fact. The question for the Tribunal is whether it is satisfied, beyond all reasonable doubt, that there are insufficient grounds for granting the claim; it will disallow a claim if it is satisfied beyond reasonable doubt that "any fact necessary to establish entitlement" (Law, at p.652) does not exist. Secondly, it remains the duty of the Tribunal to decide questions of credibility even where the witnesses who are in conflict are expert witnesses, for example, where a challenge is made to the standing or expertise of the expert in question or when the basis of the expert's opinion is destroyed in cross-examination.

18. The Solicitor-General referred to a report made in 1975 into the repatriation system by Toose J., then a Judge of the Supreme Court of New South Wales, and which led to the amendment of s. 47 by the Repatriation Acts Amendment Act 1977. We can find nothing in the report or in the second-reading speech of the responsible Minister to affect the conclusion to which we have come.

19. We would dismiss the appeal.

MURPHY J. Consistently with Repatriation Commission v. Law (1981) 147 C.L.R. 635, it was open to the Administrative Appeals Tribunal to reject the appeal because it was satisfied beyond reasonable doubt that there were insufficient grounds for granting it. The provisions of the Repatriation Act 1920 (as amended) do not mean that the Commission must grant a claim, or the Tribunal must allow an appeal, if there is some evidence which supports the claim or appeal. The Act contemplates that there will be cases in which the Commission or the Tribunal, faced with a conflict of evidence, will resolve that conflict so as to be satisfied beyond reasonable doubt that there are insufficient grounds. The Act is generous, but to read it so that the Tribunal is bound to allow the appeal in a case such as this, is to undermine Parliament's intention.

2. The Tribunal's decision to reject the appeal was amply supported by powerful evidence and to my mind, persuasive reasoning. There was no error of law. I agree generally with Mr Justice Brennan. The appeal should be allowed, the judgment of the Federal Court set aside, and instead the appeal to that Court should be dismissed.

BRENNAN J. The respondent, Mr O'Brien, who is partially incapacitated by essential hypertension, applied to the Repatriation Review Tribunal for review of decisions made by the Repatriation Commission, disallowing his claim for a war pension and medical treatment for that condition. The claim was made in October 1974 under s.101 of the Repatriation Act 1920 (Cth) ("the Act"). It is common ground that Mr O'Brien's claim should be granted if his essential hypertension "has arisen out of or is attributable to war service" within the meaning of that expression in s.101(1)(b). Mr O'Brien served in the Second World War. The Commission rejected the claim because it found that the necessary connexion between Mr O'Brien's essential hypertension and his war service did not exist. Pursuant to s.107VZZB of the Act, his application for review of the Commission's decision was referred to and determined by the Administrative Appeals Tribunal ("the AAT") for decision. The AAT affirmed the Commission's decisions.

2. Mr O'Brien then appealed to the Federal Court. A Full Court of the Federal Court (Sweeney, Keely and Fitzgerald JJ.) allowed the respondent's appeal from the AAT's decision, set aside that decision and ordered that the respondent's claim for a war pension be granted. The present appeal is brought by special leave from the Federal Court's order. The Federal Court's order that Mr O'Brien's claim be granted depends on the conclusion that the AAT, on the material before it, was bound to decide in Mr O'Brien's favour the issue of the existence of the necessary connexion between his essential hypertension and his war service. The Federal Court's jurisdiction to hear an appeal from the AAT does not authorize the Court to substitute its findings of fact for the findings of the AAT, for an appeal lies to the Federal Court only on a question of law (Administrative Appeals Tribunal Act 1975 (Cth) ("the AAT Act"), s.44). The Court does not rehear the matter, either de novo or on the materials before the AAT. I respectfully agree with the comment of the Full Court of the Federal Court (Fox, Deane and Morling JJ.) in Collins v. Minister for Immigration and Ethnic Affairs (1981) 36 A.L.R.598, at p.601, that -

" ... the concepts of a decision being against the evidence and of being against the weight of the evidence belong to appeals from courts of law and have particular application to jury verdicts. Even in that context, they do not involve questions of law. They certainly have no place when the appeal, or review, is of proceedings of an administrative tribunal which is not bound by the rules of evidence and which, subject to the obligation to observe the requirements of natural justice, can inform itself as it chooses: see s 33(1)(c) of the Administrative Appeals Tribunal Act 1975."

Thus the Court had no jurisdiction to determine in Mr O'Brien's favour the issue of the connexion between Mr O'Brien's essential hypertension and his war service unless the AAT, on the material before it, was bound as a matter of law so to determine that issue. The Full Court held that the AAT was so bound, Keely and Fitzgerald JJ. saying that the AAT -

" ... could not have been satisfied beyond reasonable doubt that the appellant's essential hypertension is not attributable to stress to which he was subjected during and by his war service."

Sweeney J. was of the same view. If their Honours were right in saying that the AAT, on the material before it, could not have been satisfied beyond a reasonable doubt that Mr O'Brien's hypertension is not attributable to his war service, Mr O'Brien was entitled to have his claim granted by reason of s.47(2) of the Act. That section governs the finding of facts by the AAT (see s.43 of the AAT Act) as well as the finding of facts by the Repatriation Commission and the Repatriation Board. Had the Commission's decisions been reviewed by the Repatriation Review Tribunal - the usual Tribunal to review the Commission's decisions - other but similar provisions would have governed the performance by that Tribunal of its review functions: see ss.107VG, 107VH. Section 47 provides:

" 47.(1) The Commission, or a Board, in hearing, considering, determining or deciding a claim or application, and the Commission, in hearing, considering or deciding an appeal - (a) is not bound by technicalities, legal forms or rules of evidence; and (b) shall act according to substantial justice and the merits and all the circumstances of the case, and, without limiting the generality of the foregoing, shall take into account any difficulties that, for any reason, lie in the way of ascertaining the existence of any fact, matter, cause or circumstance, including any reason attributable to - (i) the effects of the passage of time, including the effect of the passage of time on the availability of witnesses; or (ii) an absence of, or a deficiency in, relevant official records, including an absence or deficiency resulting from the fact that an occurrence that happened during the service of a member of the Forces was not reported to the appropriate authorities. (2) The Commission or a Board shall grant a claim or application, and the Commission shall allow an appeal, unless it is satisfied, beyond reasonable doubt, that there are insufficient grounds for granting the claim or application or allowing the appeal, as the case may be."

Section 47(2) is a piece of legislative legerdemain. It ensures that, in the administration of the Act, the fulfilment of the prescribed criteria of eligibility for war pensions - in this case the criteria prescribed by s.101 - should not be required, but that claims be granted unless it appears beyond reasonable doubt that those criteria are not fulfilled. In the present case, the relevant criterion prescribed by s.101 is that Mr O'Brien's essential hypertension be attributable to his service in the Second World War. By reason of s.47(2), he is entitled to have his claim for a war pension granted unless the AAT was satisfied beyond reasonable doubt that his essential hypertension is not attributable to that service. A provision that a claim be granted unless a negative appears beyond reasonable doubt suggests that an absence of material tending to prove the existence of the criteria of eligibility must result in the granting of a claim. The provisions of s.47(2) need not be construed to have and, in my opinion, do not have so absurd an operation.

3. Although s.47(2) employs a phrase, "beyond reasonable doubt", that is familiar in criminal proceedings, the subsection is intended to apply to proceedings which are inquisitorial, not adversarial. The Commission and the Board are concerned with the determination of a claim made in accordance with s.24AA and investigated pursuant to s.24AB. The claimant bears no onus of proof but he may support his claim by such evidence as is available to him (s.24AA(1)(b) and (2)). When the investigation is complete the whole of the material is submitted to the Board (or, when the Commission so directs, to the Commission) for its consideration and determination (s.24AB and s.27(2)). Section 47 thus operates in a context where an investigation has been carried out with reasonable diligence and where all the relevant facts ascertained in the investigation and furnished by the claimant are before the decision-maker. If the facts thus ascertained support a reasonable hypothesis that the claimant is entitled to a benefit under the eligibility provisions of the Act, the Board or the Commission must determine to grant the claim. If a reasonable hypothesis of entitlement arises on some of those facts, the Board or Commission must determine to grant the claim unless other facts dispel the hypothesis beyond reasonable doubt. If the Board or Commission is satisfied that no reasonable hypothesis of entitlement is supported by the facts or that any such reasonable hypothesis is dispelled beyond reasonable doubt, the Board or Commission should reject the claim. Where, on the whole of the material no reasonable hypothesis of entitlement arises, there are "insufficient grounds for granting the claim". In Repatriation Commission v. Law (1981) 147 C.L.R.635, Aickin J. (in whose judgment Gibbs C.J., Stephen and Mason JJ. agreed) said (at p.651):

" The expression 'insufficient grounds' must include, though it

may not be limited to, the conclusion that the evidence does not establish on the relevant standard of proof the absence of the requisite connexion between the carcinoma and war service."

4. Where, after an investigation has been carried out with reasonable diligence, there is simply no material to raise an hypothesis that the requisite connexion exists between a morbid condition and war service, the absence of such a connexion can be inferred beyond reasonable doubt. The inference arises from the absence of any material to suggest the contrary. In determining whether a reasonable hypothesis of entitlement is supported or dispelled by the facts, the Board or Commission is bound to take into account the matters set out in s.47(1)(b). Although the powers conferred on the Commission and the Board by s.26 to summon witnesses, to take evidence on oath, to compel the answering of questions and to require the production of documents are powers more frequently granted to judicial than to administrative bodies, there is no reason to suppose that the Commission or the Board are judicial bodies. Section 47(2) directs the exercise of an administrative power, not the resolution of an issue in contest between adversaries before a judicial tribunal.

5. It is only when the proceedings pass beyond the Commission and the Commission assumes a role of defending the decision it has made that it is possible to speak of an onus of proof resting on the Commission. No doubt it is convenient in proceedings before the AAT for the Commission to adopt that role but, if the Commission chose not to appear, the function of the AAT would nevertheless be to exercise the powers and to perform the function cast upon the Commission by s.28 (see the AAT Act, s.43). The Commission may be said to bear an onus only in the sense that it appears and defends its decision - a decision that will be reversed if the material before the AAT raises an hypothesis of entitlement and the hypothesis is not dispelled. The AAT must act on the whole of the material before it, which may and usually does include material that was not before the decision-maker whose decision is under review: cf. Builders Licensing Board v. Sperway Constructions (Syd.) Pty.Ltd. (1976) 135 C.L.R.616, at p.621.

6. In Law's Case there was a conflict between medical reports. One report expressed the opinion that there was a causal connexion between the death of the deceased serviceman and the habit of smoking which was found to be attributable to his war service. Other reports expressed the opinion that there was no such connexion. All reports appeared inherently reasonable and all were given by medical practitioners of unimpugned competence. It was held that an administrative decision-maker who merely looked at the reports could not find that an hypothesis of entitlement had been dispelled beyond reasonable doubt. The probative effect of the opinion supporting the claim had not been destroyed. The means by which it might have been attacked were not at hand. Aickin J. said (at p.651):

" The Review Tribunal appears to have preferred the opinion of the Commission's medical officers to that of Sir Edward Dunlop. In a civil court it would be necessary for the judge, or the jury if there were one, to hear oral evidence from the expert witnesses and to resolve any conflict on the balance of probabilities, taking into account the impression given by each expert witness. The Review Tribunal in the present case was in a very different position. In the first place it had only the written reports of the expert witnesses. Moreover it was required to find in favour of the applicant unless it was satisfied beyond reasonable doubt that there were insufficient grounds for doing so. Thus a heavy onus was placed upon the Commission to satisfy the Tribunal beyond reasonable doubt of that negative proposition. Although the medical reports were in conflict, no challenge appears to have been made to the standing or expertise of any of the medical experts. In that situation it is difficult indeed to see how the Tribunal could properly have been satisfied beyond reasonable doubt that the reports favourable to the applicant were wrong."

7. In the Federal Court, Bowen C.J., Lockhart J. and I had said ((1980) 31 A.L.R.140, at pp.153-154):

" When all that appears are contradictory medical opinions expressed in written reports by medical practitioners of good repute, in general a finding that one of those opinions is untenable cannot be made unless that opinion is inherently incredible, or the other opinion or the evidence of other witnesses exposes a manifest error in it, or its incredibility appears on examination or cross-examination of its author. Sir Edward Dunlop's opinion was not shown to be untenable: all that was shown was that a different opinion was held by other reputable medical practitioners."

But where the material before a decision-maker gives rise to competing hypotheses, one affirming an entitlement, the other denying that entitlement, and it is possible rationally to determine whether the affirmative hypothesis is dispelled beyond reasonable doubt, it is the function of the Board, the Commission or the AAT, as the case may be, to decide the question. Whether it is possible rationally to dispel an affirmative hypothesis and to destroy the probative effect of material supportive of the claim in a particular case depends on the material before the decision- maker. An opinion expressed in or a fact suggested by the material may be contradicted by ordinary experience or be otherwise inherently incredible. Or the material supportive of the claim may be internally inconsistent. Or the material obtained from the opposed medical experts, especially evidence given under cross-examination, may reveal that an opinion in favour of entitlement is vitiated by a mistake of fact or by inconsistency with received contemporary medical science. Or a lack of personal credibility may deny credit to material emanating from a particular source. Or it may be a combination of factors that leads the decision-maker to reject the hypothesis of entitlement. There are various means by which a decision-maker may properly be satisfied beyond a reasonable doubt that an affirmative hypothesis is dispelled and the probative effect of supportive material is destroyed. Provided there are grounds on which the decision-maker can be satisfied rationally that the hypothesis of entitlement has been dispelled beyond reasonable doubt, it is his function to decide whether he is so satisfied. Where there are rational grounds available for resolving a conflict in medical opinion, the decision-maker does not perform his duty by pointing to the conflict and saying that the mere existence of the conflict binds him to find in favour of the claim. To decide a claim in that way is to abdicate the function of determination cast upon him by the Act and to relegate the decision on the critical issue to the expert whose opinion supports the claim. I venture to repeat a passage from the judgment of Dixon J. in Hocking v. Bell (1945) 71 C.L.R.430, at p.496, which I cited in Chamberlain v. The Queen (1984) 58 A.L.J.R.133, at p.168 (51 A.L.R.225, at p.290):
" Scientific evidence, even when composed in part of text-books, is no less matter of fact within the province of the jury than is other evidence, and it is the jury's function to estimate the reliance to be placed on scientific witnesses, however eminent."

8. I do not understand the authority of this statement to be in doubt. If it be wrong, it would be impossible for a tribunal of fact to adjudicate between conflicting scientific opinions. Yet it is clear from the judgments in this Court and in the Federal Court in Law that the decision-making body might decide between conflicting medical opinions provided the means for doing so are at hand. This is, in my opinion, such a case.

9. The AAT had before it the material that had been before the Commission and some further medical reports. Oral testimony was given by medical practitioners who had furnished reports, and their opinions were tested under cross-examination. The AAT tested the bases of conflicting medical opinions as to the connexion between Mr O'Brien's essential hypertension and his war service. The AAT concluded that although there was medical evidence to support the claim the countervailing medical evidence had shown it to be wrong. In my opinion, the AAT had grounds on which it was entitled to find beyond reasonable doubt that there was no causal connexion between Mr O'Brien's essential hypertension and his war service. Such a finding by the AAT could not be reversed by the Federal Court on appeal.

10. However, in the Federal Court, Sweeney J. did not think that the AAT had grounds for finding that there was no connexion between Mr O'Brien's essential hypertension and his war service. His Honour noted that a Dr Finlayson had concluded that "the anxiety and stress (Mr O'Brien) suffered during his four and half years with the RAAF would be the major factor in potentiating the development of hypertension". Following the observations made by the Federal Court in Law, his Honour said:

" In the light of Dr Finlayson's evidence, the Tribunal could not properly have been satisfied beyond reasonable doubt that there were insufficient grounds for granting the claim. The other medical evidence did not destroy Dr Finlayson's opinion. His opinion was not untenable or inherently incredible, nor was any manifest error in it exposed by the other medical evidence. All that was shown was that a different opinion was held by other reputable medical practitioners. It was conceded by other medical witnesses that the opinion that stress may be a cause of the development of essential hypertension was a respectable one."

11. Keely and Fitzgerald JJ. did not go so far. Their Honours expressed "the gravest doubts" whether the AAT, having before it a serious conflict of expert evidence as to whether there was a connexion between the respondent's war service and his essential hypertension, could have been satisfied beyond reasonable doubt that there was no connexion. Although the opposing medical opinions were given by experienced and competent medical practitioners, the exhaustive examination of those opinions before the AAT, the exposure of the reasons for holding them, the statements of contemporary medical knowledge and the facts of the case, especially the delay of 26 to 28 years from the termination of Mr O'Brien's war service to the onset of his essential hypertension, provided grounds which entitled the AAT to find beyond reasonable doubt that there were insufficient grounds for granting the claim. The grave doubts which Keely and Fitzgerald JJ. expressed were instilled in part by a passage taken from the reasons for judgment of Gibbs C.J. and Mason J. in Chamberlain. That was a case where it was held that an appeal lay on the grounds that "it would be unsafe or dangerous to allow the verdict to stand" (at p.138 (p.234)), but the appeal to the Federal Court lies on the sole ground of error of law.

12. The principal ground on which Keely and Fitzgerald JJ. allowed the appeal to the Federal Court was that the AAT's reasons "taken as a whole, indicate that it was not satisfied beyond reasonable doubt that Mr. O'Brien's post-war stress ... did not have a causal relationship with his essential hypertension" and, "(t)hat being so, the evidence could not have persuaded it beyond reasonable doubt that the war-time stress did not have such a relationship". With respect, I do not think their Honours correctly understood what the AAT had found. The AAT's summary of findings is set out in the majority judgment. It is necessary to understand the nature of the conflict before the AAT in order to appreciate their findings. On one side there was material to show that a condition of anxiety state or anxiety neurosis which Mr O'Brien developed during or after his period of war service was attributable to that service and that Mr O'Brien's essential hypertension was, or might reasonably be thought to be, causally related to his anxiety state. On the other side, there was material to show that the anxiety state was not attributable to war service and that Mr O'Brien's essential hypertension was not causally related to his anxiety state or otherwise attributable to his war service. The first finding to which it is necessary to refer is that the anxiety state which Mr O'Brien developed during or after his war service was not attributable to that service although the causes of that condition were directly attributable to his serving in the forces and wishing to serve overseas at a time when his wife needed him at home to comfort and support her. This finding appears to me to mistake the meaning of the expression "attributable to war service" in s.101(1)(b). As the causes of Mr O'Brien's anxiety state were attributable to war service, it was erroneous to regard the condition thus caused as not attributable to war service. However, a reversal of this finding does not conclude the issue in Mr O'Brien's favour. The critical issue is whether there is a causal relationship between the anxiety state that has manifested itself during or shortly after the War and that had been caused by stress due to war service and the essential hypertension that manifested itself in later years.

13. The findings made by the AAT on the critical issue were three in number. Their meaning appears more clearly when they are read in conjunction with the analysis of the evidence made by the AAT. First, it was found:

" The applicant's hypertension arose out of or was developed by reason of constitutional factors."

I understand the AAT to mean that Mr O'Brien's natural constitution, not stress nor stress-induced anxiety state, gave rise to his essential hypertension. This appears from the AAT's acceptance of an opinion given by Professor Doyle, a Professor of Medicine at Melbourne University, and the evidence of Dr. Brender, a specialist cardiologist. The AAT cited a passage from Professor Doyle's report as follows:

" The evidence in Mr. O'Brien's case is that his blood pressure failed to rise even to borderline levels at any time during his war service or for 24 years after his discharge from the Air Force, during a period in which he was seen very frequently for a wide variety of symptoms. In my opinion this sequence of events makes a causal relationship between his war service and the development of hypertension so remote as to be inconceivable."

The AAT said that Dr Brender -

" could find no evidence to suggest that his hypertension arose other than on constitutional grounds; therefore, he has the true essential hypertension. Whilst he had an undoubted psychiatric illness diagnosed as anxiety neurosis, there is no relationship between his condition and his essential hypertension ...".

The second critical finding was in these terms:

" Any stress which may have aggravated the applicant's anxiety neurosis or aggravated or contributed to the development of his condition of hypertension did not arise out of nor was it attributable to his said war service."

In an earlier passage of their reasons, the members of the AAT said:

" In our opinion the applicant's condition of hypertension and hence what degree of incapacity, if any, resulted from it, developed, as is common ground, after his discharge; and from events and conditions occurring then and operating on receptive genetic and inborn factors being part of his constitutional make-up. This accords with the B.P. readings, the weight of evidence we accept as to the significance of them, and the long period before it could be said there was established a condition of essential hypertension. If stress or the anxiety state played any part in this development, we are satisfied that it was stress which bore upon the applicant by reason of the attitude post war of his colleagues at work."

The second critical finding thus denies that any external factor that occurred before Mr O'Brien's discharge was causally related to his essential hypertension. The third critical finding was in these terms:

" The applicant's incapacity from his condition of essential hypertension did not arise, was not attributable to and was not aggravated or accelerated by his war service."

I understand that finding to mean that, if stress could be regarded as a possible cause of essential hypertension, the war-time stress was not a cause of Mr O'Brien's condition. The finding is more fully stated in this passage:
" If, then, essential hypertension which we consider arose in one who was, because of his physical make-up, susceptible to it, could be produced, accelerated or produced by stress, the period 1946-1957 was the significant area in the progress of his condition, even then his essential hypertension was not established until some 16 years later. This is consistent with Professor Doyle's view as to the proximity in point of time between stress (as a possible cause or contributor to essential hypertension and its development), and with Dr Ferguson's view that if one were to postulate environmental stress as having an effect on hypertension, it was more likely to arise in the period 19 years after his discharge."

14. As I understand these findings, it is not accurate to say that the AAT was not satisfied that there was no causal relationship between stress and Mr O'Brien's essential hypertension. And if the AAT stated that it was so satisfied, it is impossible to suppose that the AAT, constituted by McGregor J., Mr Mahony, the then President of the Repatriation Review Tribunal, and Dr E.L. Davis, who cited extensively from the judgments in Law in their reasons for decision, had overlooked the "standard of disproof" required by s.47 before they made the findings adverse to Mr O'Brien's claim. They went on to find that, even if the possibility of a causal relationship between the essential hypertension and post-war stress was admitted, there could not have been any relationship between that condition and war-time stress. There was medical evidence that war-time stress was too remote in time to have had any effect in inducing Mr O'Brien's essential hypertension, and the AAT was entitled to accept that evidence. I would therefore hold that the Federal Court was in error in determining the issue contrary to the determination made by the AAT.

15. Keely and Fitzgerald JJ. perceived a further ground for setting aside the AAT's decision to affirm the Commission's refusal to grant the respondent's claim, though their Honours would have remitted the matter to the Tribunal if this had been the only error of law that they had perceived. Their Honours thought that the AAT had failed "to expose a satisfactory process of reasoning which led to the rejection of (Mr O'Brien's) claim" and that the Court "should regard a failure to comply adequately with the obligation to give reasons as itself constituting error of law, at least when a claim to a pension is rejected". It is not clear to me that the AAT did fail to expose its reasons for rejecting Mr O'Brien's claim but, in any event, a failure by a tribunal adequately to fulfil its statutory obligation to state the reasons for making an administrative decision does not, without more, invalidate the decision or warrant its being set aside by a court of competent jurisdiction. If a failure to give adequate reasons for making an administrative decision warrants an inference that the tribunal has failed in some respect to exercise its powers according to law (as, for example, by taking account of irrelevant considerations or by failing to consider material issues or facts), the Court may act upon the inference and set the decision aside. In such a case, the exercise of the statutory power to make a decision is held invalid not because of a failure to state the reasons for making the decision, but because of a failure to make the decision according to law: see Denver Chemical Manufacturing Co. v. Commissioner of Taxation (N.S.W.) (1949) 79 C.L.R.296, at p.313; Sullivan v. Department of Transport (1978) 20 A.L.R.323, at pp.348,349,352. An obligation to give oral or written reasons for a decision is cast on the AAT by s.43(2) of the AAT Act, but the remedy for a failure to fulfil that obligation adequately is a mandatory order by the Court to do so. An AAT decision, if it is made in accordance with the statutory provisions that govern the exercise of its power, is not invalidated by a mere failure to expose fully the reasons for making it. In my opinion the reasons given by the AAT in this case do not warrant an inference that it failed to review the Commission's decisions according to law.

16. The respondent submitted that another error of law appeared in the AAT's statement of its reasons. The AAT refused to accept a finding made by a Repatriation Board on 9 November 1961 that the respondent was suffering from an anxiety hysteria due to war service. When that finding was first made, the condition was assessed as causing negligible disability, but the assessment was subsequently increased. No review of the finding had been sought by any party pursuant to s.31. It was submitted that, unless that power was exercised, the AAT was bound to act on the Board's decision that Mr O'Brien's anxiety hysteria was attributable to war service.

17. I agree, for reasons stated above, that the AAT ought to have found Mr O'Brien's anxiety state to be attributable to war service, but the error which infected the finding as to that issue does not affect the conclusion that his essential hypertension was not causally related to his war service. Had it been necessary to decide the question, it seems to me that there are difficulties in the way of holding that an unreviewed Board decision accepting a condition as being attributable to war service is binding on the AAT when it is reviewing a decision made on a claim in respect of a different condition. No issue estoppel arises, nor does a finding in the later proceedings affect an entitlement flowing from the earlier finding.

18. In my opinion, the AAT's decision was not affected by an error of law. Therefore the Federal Court ought not to have set the AAT's decision aside. That decision should be restored. I would allow the appeal, set aside the judgment of the Federal Court and in lieu thereof order that the appeal from the AAT to that Court be dismissed.

Orders

Appeal dismissed with costs.