EXPERT EVIDENCE Information Session for Expert Witnesses

Transcription

1 FINANCIAL INSTITUTIONS ENERGY INFRASTRUCTURE AND COMMODITIES TRANSPORT TECHNOLOGY EXPERT EVIDENCE Information Session for Expert Witnesses 10 February 2010 Keith Redenbach Partner Construction and Engineering +61(0)

2 Introduction Part One: The Expert Part Two: Practical Considerations Part Three: Conclusions

3 PART Who is an Expert? 79(1) of the Evidence Act 1995 (NSW): 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.

4 1.2 What is expert evidence? Opinion based on fact: R v Turner [1975] QB 834 at 840 Lawton LJ said: Before a court can assess the value of an opinion it must know the facts upon which it is based. If the expert has been misinformed about the facts or has taken irrelevant facts into consideration or has omitted to consider relevant ones, the opinion is likely to be valueless.

5 1.2 What is expert evidence? cont d R v Fowler (1985) 39 SASR 440: Expert evidence will be rejected if: the facts do not require further explanation: or; on the proven facts a judge or jury can form their own conclusions without help, then the opinion of an expert is unnecessary.

6 1.2 What is expert evidence? cont d The facts are overly complex and difficult to identify: This is complex litigation and the facts in respect of which Dr Williams purported to express his opinion were not admitted by the respondents. Indeed, the facts, and the proper inferences or conclusions to be drawn from the facts contended for by the Commission, were vigorously disputed by the respondents over the many months of this litigation. In those circumstances, it is impossible for the court to know what facts Dr Williams had in mind when expressing his views.

7 1.3 Expert must not take the place of the Court Sir Richard Eggleston s text, Evidence, Proof and Probability (2nd ed, 1983): What the rule really means is that an expert must not express an opinion if to do so would involve unstated assumptions as to either disputed facts or propositions of law. Thus an expert who says `In my opinion this accident was caused by... ` in a case where the facts are disputed is assuming the right to make a decision as to which of the parties is telling the truth, and is therefore usurping the function of the tribunal. Similarly, if a valuer is called in a case where the `unimproved value' of a property is in issue, and there is uncertainty as to the meaning of the term as a matter of law, the expert should not say `In my opinion the unimproved value is...' without stating on what interpretation of the term his opinion is based. In general, where there is uncertainty of either description, the opinion should be based on hypothetical facts, clearly stated.

8 1.3 Expert must not take the place of the Court cont d As to the material on which the expert opinion can be based, just as the non-expert who is allowed to express an opinion does so on the basis of experience, so can the expert base his opinion on his experience, without having to prove by admissible evidence all the facts on which the opinion is based... But if he wishes to cite a particular instance to the court, for example, where there is an adjoining property that has recently been sold, evidence must be given by someone who can swear to the facts relating to the sale.

9 1.3 Expert must not take the place of the Court cont d The Expert must not embellish the facts, or assume facts, without informing the court. R v Fowler (1985) 39 SASR 440 at 443, King CJ stated: The course which was sought to be adopted in the present case of asking the opinion of the witness as to the possible mental condition of the accused at the time of the alleged crime, based not upon assumed facts, but upon a reading of the whole of the evidence and the accused s account of his drug ingestions, is not acceptable and such evidence cannot be admissible.

10 1.3 Expert must not take the place of the Court cont d It involved the expert in making his own unstated findings of fact and his own interpretation of them. The jury might arrive at different conclusions of fact and a different interpretation of the facts. Clearly a witness cannot be permitted to express his findings and interpretations of fact, and there would therefore be no way by which the jury would know whether the opinion could stand in light of the jury s view of the facts. it is of the utmost importance that the assumptions of fact upon which the opinion is arrived at be clearly stated and that the evidence be confined to opinions expressed upon those stated assumed facts.

11 1.4 Summary of the Expert s Obligations It must be agreed or demonstrated that there is a field of specialised knowledge; There must be an identified aspect of that field in which the witness demonstrated that by reason of specified training, study or experience, the witness has become an expert; The opinion proffered must be wholly or substantially based on the witness s expert knowledge; So far as the opinion is based on facts observed by the expert, they must be identified and admissibly proved by the expert; So far as the opinion is based on assumed or accepted facts, they must be identified and proved in some other way; It must be established that the facts on which the opinion is based form a proper foundation for it; and the expert s evidence must explain how the field of specialised knowledge in which the witness is expert, and on what the opinion is wholly or substantially based applies to the facts assumed or observed so as to produce the opinion propounded. McDougall J, Expert Evidence

12 1.5 Whose side is the Expert on? Practice Note 104, paragraph 2: An expert witness's paramount duty is to assist the court impartially. That duty overrides the expert witness's obligation to the engaging party. An expert witness is not an advocate for a party.

13 1.5 Whose side is the Expert on? cont d An expert is not an advocate. Eggleston: The expert has a legitimate role of advocacy in that, having expounded to the tribunal the rules applicable to the case (these may not even be in dispute), his evidence may then consist of argument as to the conclusions that should be drawn from the facts, interpreted in the light of those rules. The difficulty arises because the expert often finds it difficult to distinguish between argument on the assumption that the facts put forward by his side are the correct ones, and telling the judge or jury which facts they should accept as true. If he makes his assumption clear, there is no objection to his arguing what the consequences of accepting those assumptions should be; but he is not to do the jury's fact-finding for it, where this depends on accepting one or the other set of contradictory witnesses.

14 PART 2 Uniform Civil Procedure Rules 2005 (NSW) Part 31, Division 2 was amended in 2006 to address the increasing concern of the legal and professional community as to the use and abuse of expert witnesses. The following consists of commentary on the rules deemed relevant to the practice of expert witnesses.

15 Uniform Civil Procedure Rules 2005 (NSW) cont d Rule Main purposes of Division Rule Parties to seek directions before calling expert witnesses Rule Court may give directions regarding expert witnesses Rule Expert witnesses to provide details of contingency fees or deferred payment schemes

16 Uniform Civil Procedure Rules 2005 (NSW) cont d Rule Conferences between expert witnesses Rule Instructions to expert witnesses where conference ordered before report furnished Rule Experts Reports Rule Opinion evidence by expert witnesses

17 Uniform Civil Procedure Rules 2005 (NSW) cont d Parties single experts and Court Experts Rule Selection and engagement Rule Parties single expert may apply to court for directions Rule Parties may seek clarification of report Rule Parties may seek clarification of courtappointed expert

18 PART 3 Conclusions The role of the expert is an invidious one. The expert must balance the duty to the court with the interests of the instructing client. Nevertheless, regardless of all these considerations, the expert must at all times utilise facts in his or her opinion otherwise, the opinion is redundant. Examining the substance of an opinion cannot be carried out without knowing the essential integers underlying it : Makita (Australia) Pty Ltd v Sprowles (2001) NSWLR 705, 735.