Case: Sydneywide Distributors Pty Ltd v Red Bull Australia Pty Ltd (2002) 55 IPR 354 
Outcome: followed
The issue is, I think, whether Mr Stokoe, with his experience, can say what he does about how the customers in the market would have reacted to a posited choice of dry or liquid Part B in the respective dialysis systems. Mr Stokoe does not speak from the perspective of a psychologist or market research expert of the kind discussed by the Full Court of this Court in Sydneywide Distributors Pty Ltd v Red Bull Australia Pty Ltd (2002) 55 IPR 354. However, notwithstanding the fact that he does not have Dr Beaton's or Ms Strachan's background, he does, on the evidence to date, have nearly 30 years of working in the specialised and particularised market, being familiar not only with the machines, but also with the participants and their purchasing in the market. 24 In one sense, it goes without saying that he cannot say what any particular individual person would have done on a particular day. However, the evidence of the kind permitted in Red Bull 55 IPR 354, and also dealt with with a degree of generosity in Cadbury Schweppes Pty Ltd v Darrell Lea Chocolate Shops Pty Ltd (2007) 159 FCR 397, indicates that evidence in which an expert, who has some specialised knowledge which equips him or her to say something about how consumers will behave, is not inadmissible in limine as not being capable of being the subject of expert evidence. 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. 39 Weinberg and Dowsett JJ also addressed the question of Makita [2001] NSWCA 305 ; 52 NSWLR 705 from [84] and following in the section of their judgment dealing with the admissibility of Dr Beaton and Ms Strachan's evidence. It should be said that in Red Bull 55 IPR 354, the matter was different from that which lies before me here, in that the evidence, unlike the evidence today, went in at trial without objection. 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. 42 In BHP Billiton Iron Ore v National Competition Council (2007) 162 FCR 234, the Full Court of this Court once again returned to the issue. At [185] in the reasons of Greenwood J, with which Sundberg J agreed, his Honour dealt with the whole question of expert evidence as follows: The appellants contend on appeal that the evidence of the economic experts is inadmissible as irrelevant. The evidence was admitted on the basis of contextual elaboration of the extrinsic material. The evidence is relevant if it is evidence that if accepted could rationally affect (directly or indirectly) the assessment of the probability of the existence of a fact in issue in the proceeding ( Evidence Act 1995 (Cth), s 55(1)). Evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed (s 76(1)) although, if a person has specialised knowledge based on the person's training, study or experience, the opinion rule does not apply to evidence of an opinion of that person that is wholly or substantially based on that knowledge (s 79). The normal role of an expert is to give an opinion based on clearly identified facts ( Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305 ; (2001) 52 NSWLR 705), almost invariably assumed to be the facts, on the footing that those facts provide a proper foundation for an opinion within the demonstrated discipline or field of specialised knowledge of the expert witness. Although s 79 of the Evidence Act seems to operate on the footing that the opinion of a person wholly or substantially based on specialised knowledge is not precluded by s 76(1) in the absence of proven foundation facts ( Sydneywide Distributors Pty Ltd v Red Bull Australia Pty Ltd (2002) 55 IPR 354 [10]; Neowarra v Western Australia (No. 1) [2003] FCA 1399 ; (2003) 134 FCR 208), little or no weight will be given to such an opinion ( Ramsay v Watson [1961] HCA 65 ; (1961) 108 CLR 642) although the central point may simply be the question of admissibility, not weight ( HG v R [1999] HCA 2 ; (1999) 197 CLR 414 at [39] [44]; Trade Practices Commission v Arnott's Ltd (No. 5) (1990) 21 FCR 324 at 327-330). That question does not arise here. In this case, the experts did not seek to offer an economic opinion related to disputed or undisputed facts probative of a matter in issue. They sought to offer an historical or contextual explanation as an elaboration of extrinsic material going to Part IIIA of the Act. It is difficult to see how that evidence is truly admissible except perhaps in that unusual category of 'expert non-opinion evidence' descriptive of a relevant element of the economic discipline concerning the evolution of economic concepts of access to natural monopoly infrastructure, without offering any opinion about facts in issue. In any event, the material is capable of being received by the court and considered by force of Order 10, rule 1(2)(j) of the Federal Court Rules , by way of a submission rather than admissible evidence. 43 On one reading of [185], it might be seen that some variation is being made to what was said in Red Bull 55 IPR 354. I do not think that [185] should be so read. If Greenwood J were to be intending to depart from a previous Full Court of this court, he no doubt would have expressed it himself in terms of perceived error in the earlier Full Court's reasons. He did not do so. Thus, I am left with the position that I do not judge the admissibility of this material by the quality of the reasoning underpinning its expression. I judge its admissibility by coming to the view whether the opinions are based on the relevant specialised knowledge, a conclusion which I have already reached.