Case: Quick v Stoland Pty Ltd (1998) 87 FCR 371
Outcome: discussed
The first case which dealt with the question of the basis rule was a Full Court decision of this court in Quick v Stoland Pty Ltd (1998) 87 FCR 371. In that case, Branson J, with whose opinions on the structure of the Evidence Act 1995 (Cth) Emmett J agreed, expressed the view that the opinion rule, qualified it as it is in section 79 of the Evidence Act , did not incorporate the common law rule that the admissibility of expert opinion depends upon proper disclosure and proof of the factual basis of the opinion. Her Honour went on to identify that this was not an accidental omission, and that paragraph 750 of the ALRC Report No 26, volume 1 (the Interim Evidence Report) dealt with the matter expressly. 32 I should add at this point, without seeking in any way to be controversial, in particular given the debate between intermediate appellate courts, that the practice, at least in some courts in land and valuation matters in years past, can be seen not to have required a full discussion of the reasoning in valuation cases. But valuation cases may be specialised creatures of their own and I do not need to dwell on them for those reasons. 37 His Honour went on to refer to [21] to [23] of the reasons of the Full Court in Jetopay [2000] FCA 1463 ; 120 FCR 146. His Honour was apparently not referred to the decision of the Full Court of the Federal Court in Quick v Stoland 87 FCR 391. His Honour did not deal with it. However, it is fair to say that the views expressed by his Honour in [85] are contrary to those expressed by Branson J in Quick v Stoland 87 FCR 391 and, as I read Emmett J's judgment, to Emmett J's views as well. 38 The matter then returned to the Federal Court in Red Bull 55 IPR 354. Makita [2001] NSWCA 305 ; 52 NSWLR 705 was the subject of consideration by the Full Court. There were two judgments, one of Branson J, the other of Weinberg and Dowsett JJ. Branson J reiterated her views in Quick v Stoland 87 FCR 371, and in [14]-[17] made the following relevant comments upon Makita : 14. However, if Heydon JA, in the paragraph set out in [6] above, intended to use the word "sure" in its usual sense of subjectively certain, I respectfully disagree with the view that when determining the admissibility of evidence of an expert opinion (perhaps more accurately, a purported expert opinion), it is necessary for the court to be " sure whether the opinion is based wholly or substantially on the expert's specialised knowledge ". The test is whether the court is satisfied on the balance of probabilities that the opinion is based wholly or substantially on that knowledge (s 142 of the Evidence Act ). However, as identified in [12] above, satisfaction of that test is not sufficient to render the evidence of the expert opinion admissible. To be admissible the evidence must also be relevant. It is the requirement of relevance, rather than the requirement that the opinion be based wholly or substantially on the expert's specialist knowledge, that, as it seems to me, most immediately makes proof of the facts on which the opinion is based necessary. If those facts are not at the close of trial proved, or substantially proved (see Paric v John Holland (Constructions) Pty Ltd [1985] HCA 58 ; (1985) 59 ALJR 844 at 846), it is unlikely that the evidence, if accepted, could rationally affect the assessment of the probability of the existence of the fact in issue in the proceeding to which the evidence is directed. 15. A ruling on the admissibility of the evidence of the expert opinion is, however, likely to be required before the end of the trial. The possibility that a determination of relevance might need to be made before the court has made other relevant findings is recognised by s 57 of the Evidence Act . Section 57(1) provides: "(1) If the determination of the question whether evidence adduced by a party is relevant depends on the court making another finding (including a finding that the evidence is what the party claims it to be), the court may find that the evidence is relevant: (a) if it is reasonably open to make that finding; or (b) subject to further evidence being admitted at a later stage of the proceeding that will make it reasonably open to make that finding." Section 57(1)(b) would appear to authorise the admission unconditionally of provisionally admitted evidence on a standard of proof concerning relevance (ie where it is reasonably open to make the finding) which is even lower than the balance of probabilities. 16. Further, the requirement that an expert opinion be wholly or substantially based on the witness's specialised knowledge is not, in my view, intended to require a trial judge to give meticulous consideration, before ruling on the admissibility of the evidence of the opinion, to whether the facts on which the opinion is based form a proper (in the sense of logically or scientifically or intellectually proper) base for the opinion. Were the position otherwise the smooth running of trials involving expert evidence could be expected to be interrupted by the need to explore in detail, in the context of admissibility, matters more properly considered at the end of the trial in the context of the weight to be attributed to the evidence. It is sufficient for admissibility, in my view, that the trial judge is satisfied on the balance of probabilities on the evidence and other material then before the judge that the expert has drawn his or her opinion from known or assumed facts by reference wholly or substantially to his or her specialised knowledge. In many cases the relevant evidence and other material that will be before the judge at the time that the judge is required to rule on admissibility will extend little, if at all, beyond the purported expert's affidavit or report or, where only oral evidence is intended to be adduced, the earlier oral evidence of the witness and the form of the question to which objection has been taken. In the Federal Court, the usual practice of requiring expert evidence to be reduced to writing, together with the Guidelines for Expert Witnesses referred to in [13] above, will generally ensure that there is sufficient material before the judge to enable the judge to form a view, on the balance of probabilities, (albeit, in the context of the trial as a whole, a provisional view) as to whether an opinion is wholly or substantially based on the witness's specialised knowledge. In most other jurisdictions there are now comparable equivalent rules or guidelines. 17. Evidence later adduced, most likely in cross-examination, might reveal that an opinion proffered in an affidavit or report is not wholly or substantially based on the witness's specialised knowledge, or that the expert made an error (whether of logic, science or otherwise) in the process of reaching his or her opinion. While that evidence might be relevant to admissibility in a hypothetical sense, it would not, of itself, demonstrate error in the earlier ruling that the affidavit or report be received in evidence. The correctness of that ruling is to be judged by reference to the relevant evidence and other material before the judge at the time of the ruling. The evidence might, however, be of crucial importance with respect to the weight to be accorded the opinion at the end of the day. 40 In the helpful judgment, if I may respectfully say so, of Sundberg J in Neowarra v State of Western Australia [2003] FCA 1399 ; (2003) 134 FCR 208, his Honour discussed the course of this authority under the heading "The Basis Rule". He concluded from these authorities that the basis rule does not feature in section 79 of the Evidence Act , and cites and follows, as his Honour was required to, and as I am required to, the Full Court authority of this Court in Quick 87 FCR 371 and Red Bull 55 IPR 354. His Honour noted the views of Heydon JA in Makita [2001] NSWCA 305 ; 52 NSWLR 705 [85] and the views of the Full Court in Red Bull 55 IPR 354. The reality is that, subject to one matter to which I will come, if there be any difference, as I think, strictly speaking, there is, between the approach taken by Heydon JA in the Court of Appeal and the Full Court of this Court, I must follow the Full Court of this Court.