[26] In Wingfoot Australia Partners Pty Ltd v Kocak[11] the High Court said of the role of a Medical Panel:
The function of a Medical Panel is to form and to give its own opinion on the medical question referred for its opinion. In performing that function, the Medical Panel is doubtless obliged to observe procedural fairness, so as to give an opportunity for parties to the underlying question or matter who will be affected by the opinion to supply the Medical Panel with material which may be relevant to the formation of the opinion and to make submissions to the Medical Panel on the basis of that material. The material supplied may include the opinions of other medical practitioners, and submissions to the Medical Panel may seek to persuade the Medical Panel to adopt reasoning or conclusions expressed in those opinions. The Medical Panel may choose in a particular case to place weight on a medical opinion supplied to it in forming and giving its own opinion. It goes too far, however, to conceive of the function of the Panel as being either to decide a dispute or to make up its mind by reference to competing contentions or competing medical opinions. The function of a Medical Panel is neither arbitral nor adjudicative: it is neither to choose between competing arguments, nor to opine on the correctness of other opinions on that medical question. The function is in every case to form and to give its own opinion on the medical question referred to it by applying its own medical experience and its own medical expertise.[12]
[27] Whilst it is true, as counsel for Ms Landy pointed out, that this statement of principle highlights the specific function of the Panel in providing its own opinion as to the questions asked, there is nothing (at least to my mind) in the Decision that alters or adjusts earlier statements by judges of this Court of the application of principles of procedural fairness in the judicial review of medical panel decisions. I do not accept, as hinted at by senior counsel for Ms Landy, that the decision in Wingfoot in any material way alters the obligation on the Panel to accord the parties procedural fairness.
[28] The hearing rule is a fundamental part of the obligation to afford parties procedural fairness. Mason J in the seminal decision of Kioa v West[13] said as to procedural fairness and the 'hearing rule':
It is a fundamental rule of the common law doctrine of natural justice expressed in traditional terms that, generally speaking, when an order is to be made which will deprive a person of some right or interest or the legitimate expectation of a benefit, he is entitled to know the case sought to made against him and to be given an opportunity of replying to it.[14]
[29] More particularly in the context of judicial review of medical panel decisions, Cavanough J in Barrett Burston Malting Co Pty Ltd v Kotzman[15] said:
A medical panel convened to form its opinion as to medical questions referred to under the Act is bound to observe the rules of natural justice in favour of persons whose rights are liable to be affected by the discharge of that function. Failure to sufficiently accord an affected party procedural fairness or natural justice contaminates the medical panel opinion with illegality such that it is liable to be quashed upon judicial review. Examples of a medical panel's opinion being quashed upon judicial review for failure to observe "the hearing rule" of procedural fairness may be found in Calleja v Franet Pty Ltd and Weerappah v Nisselle. The leading Australian case concerning the content of the hearing rule generally is Kioa v West.
A medical panel is obliged to accord the protection of the "hearing rule" of procedural fairness to the employer/insurer party, not merely to the worker party: see, eg, Weerappah where Smith J said:
While much of the foregoing discussion is centred on the position of the worker, it must be borne in mind that there is always another party to these disputes and it too can be disadvantaged if the panel does not accord natural justice. For example, in the course of a medical examination, the worker may reveal information of which the insurer is unaware and which may, if accepted, entitle the worker to the compensation it [sic] had been denied. It would be a denial of natural justice for the insurer not to have an opportunity to address that information before the Panel reached its decision.
A medical panel can also breach the hearing rule in relying upon its own medical expertise to form an opinion - say, as to diagnosis, or, say, as to an aspect of disability previously unnoticed by other medical examiners - such that it could be said that a party did not have a fair opportunity to have that proposed adverse conclusion explored with its own experts. In such a situation, the aggrieved party has been denied a fair opportunity to be "heard" (for instance, through submitting its own medical reports or written submissions) on the issue. Calleja v Franet Pty Ltd is an example of the Supreme Court giving relief in such an instance.[16]
[30] Having considered these propositions in the context of that case - in which the Panel made an unanticipated finding that the worker was suffering from a factitious disorder - Cavanough J found that the Panel had breached the rules of natural justice:
I agree with the employer's submission that the medical panel's psychiatric diagnosis - that the worker was suffering from a "factitious disorder" - was unexpected and could not reasonably have been anticipated; and that the employer was denied a fair opportunity to address the matter. In my view, the panel's psychiatric diagnosis of a "factitious disorder" in its opinion and reasons came "out of the blue".[17]
[31] Barrett Burston was decided a couple of months prior to the decision of the High Court in Wingfoot. The principles set out by Cavanough J have been adopted and applied by other judges of this court since Wingfoot was decided. As Bell J said in H & G MacDonald Carriers Pty Ltd v Carson,[18] a case not dissimilar to the present:
Of course the Panel was an expert body and its members can rely upon their own medical expertise, as they undoubtedly did in the present case when [expressing the opinions that are under challenge]. However, relying upon their own expertise, Panel members must still give parties and interested persons a fair opportunity to be heard in relation to the matters in issue.[19]
[32] To like effect in North v Homolka,[20] Ashley JA (sitting in the Trial Division) adopted the statements of principle set out by Cavanough J noting:
In some circumstances, a panel might be obliged to fragment its consideration of a matter in order to accord a party procedural fairness. Barrett Burston was such a case. So was Calleja v Franet Pty Ltd.
But what are those circumstances? A panel is an expert tribunal. It is entitled to rely upon its expertise in making its determination. Here, the Panel's expertise was in part the expertise of Dr Homolka, an occupational physician. She might be expected to understand a good deal about job descriptions. It would go too far, and the authorities do not require it, to say that every resort by a panel to its own knowledge and expertise, not communicated to a party, will constitute want of procedural fairness. It will, I think, be a matter of fact and degree in every case, but speaking generally a want of procedural fairness is likely to be disclosed where a finding by a panel is unexpected, could not have been reasonably anticipated, or would not obviously be open on the known material. Barrett Burston and Calleja were exemplars of that kind of situation.[21]