Who must prove?
18 Where an administrative decision-maker, such as the Tribunal, is left in doubt as to whether a relevant fact exists, what course does the law dictate? In civil and criminal litigation of course there are long established rules as to the onus of proof. What happens in an administrative setting was discussed by Woodward J in McDonald. The issue there was whether the appellant was permanently incapacitated for work to the extent of 85 per cent or more so as to be entitled to an invalid pension. The appellant had received a pension but it was subsequently cancelled. Woodward J said (at 356):
"The first point to be made is that the onus (or burden) of proof is a common law concept, developed with some difficulty over many years, to provide answers to certain practical problems of litigation between parties in a court of law. One of the chief difficulties of the concept has been the necessity to distinguish between its so-called 'legal' and 'evidential' aspects. The concept is concerned with matters such as the order of presentation of evidence and the decision a court should give when it is left in a state of uncertainty by the evidence of a particular issue.
The use outside courts of law of the legal rules governing this part of the law of evidence should be approached with great caution. This is particularly true of an administrative tribunal which, by its statute 'is not bound by the rules of evidence but may inform itself on any matter in such manner as it thinks appropriate' (AAT Act s. 33(1)(c)).
Such a tribunal will still have to determine practical problems such as the sequence of receiving evidence and what to do if it is unable to reach a clear conclusion on an issue, but it is more likely to find the answer to such questions in the statutes under which it is operating, or in considerations of natural justice or common sense, than in the technical rules relating to onus of proof developed by the courts. However these may be of assistance in some cases where the legislation is silent.
Whether the principles adopted by such a tribunal, arising from these various considerations, are appropriately dealt with under the heading 'onus of proof', becomes a matter of choosing labels. It would probably be more convenient to avoid using that expression in cases such as the present.
There is certainly no legal onus of proof arising from the fact that this is an 'appeals' tribunal, because the AAT is required, in effect, by s. 43 of the AAT Act, to put itself in the position of the administrator in carrying out its review and, in the light of the material before the AAT, (not the material before the administrator, Drake v Minister for Immigration and Ethnic Affairs 91979) 46 F.L.R. 409 at 419) make its own decision in place of the administrator's. The AAT itself, in a series of cases beginning with re Ladybird Children's Wear Pty Ltd (1976) 1 A.L.D. 1, has taken the view that there is no presumption that the administrator's decision is correct. This is clearly the right approach to the matter.
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The next question which arises is whether once an invalid pension has been granted, there is an evidential onus on the Director-General to satisfy himself, or on appeal the AAT, of changed circumstances before cancelling the pension. This was the main issue argued before us under the first question of law.
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It is true that facts may be peculiarly within the knowledge of a party to an issue, and a failure by that party to produce evidence as to those facts may lead to an unfavourable inference being drawn - but is not helpful to categorise this common-sense approach to evidence as an example of an evidential onus of proof. The same may be said of a case where a good deal of evidence pointing in one direction is before the Tribunal, and any intelligent observer could see that unless contrary material comes to light that is the way the decision is likely to go. Putting such cases to one side there can be no evidential onus of proof in proceedings before the AAT unless the relevant legislation provides for it, and in the present case the Social Security Act 1947 (Cth) does not.
If the AAT finds itself in a state of uncertainty after considering all the available material, unable to decide a question of fact either way on the balance of probabilities, it will be necessary for it to analyse carefully the decision it is reviewing. If, for example, it is a decision whether or not to cancel a pension in the light of changed circumstances, then it has failed to achieve the statutory requirement of reaching a state of mind that the pension should be cancelled. If, on the other hand, it is a decision, to be made in the light of fresh evidence, whether or not the pension should ever have been granted in the first place, then it has failed to be satisfied that the person ever was permanently incapacitated for work. For a comparable analysis as to the onus of proof (properly so-called) before a judicial tribunal see Phillips v. The Commonwealth (1964) 110 C.L.R. 347 at 350."
19 Phillips (1964) 110 CLR 347 concerned a Commonwealth employee who was receiving compensation under the Commonwealth Employees' Compensation Act 1930 (Cth) ("the 1930 Act"). A Delegate of the Commissioner made a determination that the appellant had been able to earn in some suitable employment or business a weekly amount which was not less than her pay at the date of injury and thereupon she ceased to be entitled to weekly payments of compensation. After referring to s 20(1) of the 1930 Act the High Court (Kitto, Taylor and Owen JJ) said (at 350):
"… upon any such review it is, we think, for the Court to pronounce anew upon the rights of the parties as disclosed by the evidence before it. That being so the application of the ordinary principles relating to the determination of disputed questions of fact by judicial tribunals requires the conclusion that if a claim for compensation be rejected by the Commissioner or his delegate the onus of proving the necessary facts to entitle the applicant to what is virtually an award of compensation will be upon the claimant in later proceedings before the County Court. Likewise, the application of the same principles may well mean that in some cases the onus of proving critical facts may rest upon the Commonwealth. Such a case would be where the Commissioner has purported to terminate an employee's right to compensation under an antecedently existing determination by reason of a material change of circumstances. This proposition was disputed by the Commonwealth on the authority of observations made in Pethick v. The Commonwealth of Australia (1960) 103 CLR 643 at 649, but that case was not concerned with the termination of a right to compensation by reason of any change in material circumstances; it was concerned with the question whether the appellant ever had a right to compensation."
20 The facts of Phillips are instructive for present purposes. On the rehearing of the employee's appeal in the County Court of Victoria it was found in fact that she was not totally incapacitated. But she claimed that she was partially incapacitated or at any rate that the onus was on the Commonwealth to prove that she was not. The High Court said (at 351):
"In the first place, there arose for determination the question whether the liability of the Commonwealth to pay compensation to the appellant as a totally incapacitated employee should be brought to an end. Upon this issue the onus rested fairly upon the Commonwealth but, as already appears, it was discharged and the finding of the County Court cannot be challenged. Then arose the question whether compensation should be awarded to the appellant as a person partially incapacitated and with a diminished earning capacity. This, in effect, constituted the basis of a new claim not previously pronounced upon before its rejection by the Commissioner. On this issue the onus was, we think, clearly upon the appellant. Accordingly, we do not think that the learned County Court Judge made any error of law upon this point."
21 In The Commonwealth v Muratore (1978) 141 CLR 296 an employee had received compensation under the 1930 Act. A determination was made that he was able to earn an amount in suitable employment and his compensation was reduced to $11.94 per week. A further determination was made that he was able to earn an amount not less than his weekly pay, as a consequence of which he was not entitled to compensation at all. The employee argued that the onus of proof of matters which would entitle the Commonwealth to reduce his compensation from $11.94 per week to nil lay upon the Commonwealth. The High Court (Jacobs J, with whom Gibbs and Stephen JJ agreed) cited with approval the statement of the Master of the Rolls in Cory Brothers & Co Ltd v Hughes [1911] 2 KB 738 at 743:
"… there is an express power given to either party to review the amount of compensation, which may be either increased or diminished or terminated. The employer may say 'I am now paying you too much'; the man may say 'You are now paying me too little'; or the employer may say 'I ought now to pay you nothing at all.' But whoever makes that application is the person on whom the burden of proof lies. Here it is to my mind impossible to escape from the conclusion that the burden is on the employers to satisfy the Court that the man at this moment is not under any incapacity by reason of the accident which admittedly befell him."