Plaintiff v Defendants

2 Senior Counsel for Mrs Matthews asked the following question:

Mr Walley, there's evidence in this case that there was a pitting on this conductor near the helical fit at pole 39 and with the passage of time there was a propagation of this pitting, so as to result in fracture of one strand and then fracture of another strand with the first strand fracturing some months before the second strand, and then after the second strand fracturing a ductile fracture of the third strand, and that the pitting that was at the point where the fractures occurred, occurred many years prior to February 2009. If that be so, had there been a damper fitted to this line some years prior to 2009, do you have an opinion as to whether that would have affected in any way the rate of the deterioration and ultimate fracture of the conductor?[1]

3 After objection, the question was put again as follows:

Putting those facts without repeating them, if in fact that was the situation - I will repeat them in part: an event which caused some pitting or microscopic fracture which propagated with time, so that there was a fracture of one strand of the conductor some many months before February 2007 [sic], that another strand of the conductor which had its pitting at the same time as the first strand had the fracture propagating over that period of time and fractured on 7 February 2007 [sic], causing then the third strand to give way. If that was the history in relation to this line, had there been a vibration damper fitted to this line some years before, do you have an opinion as to whether that had any potential to in some way influence the period of time that the line would have survived?---Sorry, could you just repeat that second part of the question?[2]

4 The salient part for present purposes was the following question and answer:

Do you have an opinion as to whether or not if a vibration damper had been fitted at some time, a considerable time not weeks before, some years before 2009, whether or not it would have influenced what would have happened with this line up to February 2009, and in particular, whether it could have influenced whether it fractured or not?---Yes, it would have influenced it. If you had fitted a vibration damper it would have reduced the crack propagation rate and would potentially get extra life out of the conductor.[3]

5 I held, ex tempore, that Mr Walley had sufficient specialised knowledge to express such an opinion based on his training, study and experience. I remain of that view.

6 However, the substance of the objection by SPI was that the factual bases for expressing the opinion were lacking to the point where the opinion was inadmissible. I determined that there were sufficient factual bases, that is on the basis of assumed facts, to permit the opinion to be given and that any insufficiency went to weight rather than admissibility.

7 Overnight, I reflected on my ruling ex tempore and revisited what was said by the High Court in its most recent statement on the operation of s 79 of the Evidence Act 1995 (NSW)[4] in Dasreef Pty Limited v Hawchar.[5] One issue left outstanding by the Court is whether the so-called "basis rule" remains a prerequisite to admissibility under s 79 of the Act.

8 There is, in my view, no doubt that the judgment of the majority emphasised that the primary task under s 79 is to determine that the opinion in question is one which relies upon the expert's specialised knowledge. The Court said as follows:

It should be unnecessary, but it is nonetheless important, to emphasise that what was said by Gleeson CJ in HG (and later by Heydon JA in the Court of Appeal in Makita (Australia) Pty Ltd v Sprowles) is to be read with one basic proposition at the forefront of consideration. The admissibility of opinion evidence is to be determined by application of the requirements of the Evidence Act rather than by any attempt to parse and analyse particular statements in decided cases divorced from the context in which those statements were made. Accepting that to be so, it remains useful to record that it is ordinarily the case, as Heydon JA said in Makita, that "the expert's evidence must explain how the field of 'specialised knowledge' in which the witness is expert by reason of 'training, study or experience', and on which the opinion is 'wholly or substantially based', applies to the facts assumed or observed so as to produce the opinion propounded".[6]

9 The High Court did not, however, deal in terms with the status, if any, of the "basis rule" as it applies under s 79.[7] Whilst the Court held that ordinarily such an expert must explain how his or her expertise relates to the facts, it is distinctly arguable that this is not now a prerequisite for satisfaction of the terms of s 79 by which such an opinion is rendered admissible:

Contrary to submissions on behalf of Mr Hawchar, this analysis does not seek to introduce what has been called 'the basis rule': a rule by which opinion evidence is to be excluded unless the factual bases upon which the opinion is proffered are established by other evidence. Whether that rule formed part of the common law of evidence need not be examined. It may be accepted that the Law Reform Commission's interim report on evidence denied the existence of such a common law rule and expressed the intention to refrain from including a basis rule in the legislation the Commission proposed and which was later enacted in the Evidence Act 1995 (Cth) and the Evidence Act 1995 (NSW). What has been called the basis rule is a rule directed to the facts of a particular case about which an expert is ask to proffer an opinion and the facts upon which the expert relies upon to form the opinion expressed. The point which is now made is a point about connecting the opinion expressed by a witness with the witness's specialised knowledge based on training, study or experience.[8]

10 The line of reasoning that an opinion is admissible under s 79 notwithstanding a failure to identify the assumptions of fact which underpin that opinion is supported by a number of decisions of the Federal Court since the well-known and oft cited decision of Makita (Australia) Pty Ltd v Sprowles.[9] Those decisions are: Sydneywide Distributors Pty Ltd v Red Bull Australia Pty Ltd,[10] a decision of the Full Federal Court; Quick v Stoland Pty Ltd,[11] a decision of Branson, Emmett and Finklestein JJ; Neowarra v Western Australia (No 1),[12] a decision of Sundberg J; Sampi v Western Australia,[13] a decision of French J; Gambro Pty Ltd v Fresenius Medical Care Australia Pty Ltd,[14] a decision of Allsop J; and the Tasmanian Supreme Court decision of Beswick v Tamarack Pty Limited,[15] a decision of Porter J.

11 If this line of reasoning is correct then the basis rule goes solely to the weight to be given to the opinion such that the greater the divergence from the established facts, the lesser the weight to be given to it. If that approach alone be applied in this case then the ruling I made yesterday would still stand.

12 However there is, I think, a qualification. There must be a point at which the divergence between the assumed facts and the established facts is so great that the opinion becomes irrelevant: that is, it does not satisfy the relevance test laid down by s 56 of the Act and is therefore inadmissible.

13 As Lindgren J said in Harrington-Smith & Ors v State of Western Australia (No 2):[16]

In relation to the second deficiency (failure to distinguish between assumed facts and opinion) the Evidence Act does not, in terms, require, as a condition of admissibility, that an expert witness state distinctly and fully the facts assumed as the basis of his or her opinion.

But expert opinion will not be relevant if there is an insufficient correspondence between all the facts assumed by the expert as the basis for his or her opinion, and those proved or admitted.[17]

14 At the present time I cannot determine whether the divergence, if there be any, between the assumed facts and the facts which will ultimately be established is such that it goes to a question of weight or the ultimate admissibility of Mr Walley's opinion. Accordingly, I propose to admit the evidence of Mr Walley's opinion on this issue provisionally under s 57 of the Act and allow the parties in closing submissions to further debate the question of admissibility of and weight to be given to the opinion.

[4] Section 79 of the Evidence Act 2008 (Vic) ("the Act") is identical to the New South Wales provision and to the Commonwealth provision: s 79 of the Evidence Act 1995 (Cth).

[5] [2011] HCA 21; (2011) 243 CLR 588.

[8] [2011] HCA 21; (2011) 243 CLR 588, 605. See also HG v The Queen [1999] HCA 2; (1999) 197 CLR 414.

[9] [2001] NSWCA 305; (2001) 52 NSWLR 705, 743.

[10] [2002] FCAFC 157; (2002) 55 IPR 354, 356-7, 359, 378-9.

[11] [1998] FCA 1200; (1998) 87 FCR 371, 373-4.

[12] [2003] FCA 1399; (2003) 134 FCR 208, 215-219, 223.

[13] [2005] FCA 777 [798]-[802].

[14] [2007] FCA 1828; (2007) 245 ALR 15, 27.

[15] [2009] TASSC 109 [151]-[154].

[16] [2003] FCA 893; (2003) 130 FCR 424.