Reliance upon expert evidence is a common occurrence in litigation and is often crucial to your success.
When advising as to the use of expert evidence and the preparing of expert reports, it is essential that you remain aware of the circumstances in which expert evidence is admissible and the requirements that must be satisfied by you if you seek to rely upon such evidence.
Expert witnesses used correctly can strengthen your position by adding credibility to your claim and providing an objective opinion to support your facts. It is important however that the expert is managed correctly so that their opinion can be relied upon in Court. Otherwise the Court may disregard the evidence provided by that particular expert.
In this respect, the admissibility of expert evidence is governed principally by section 79 of the Evidence Act 1995 (Evidence Act) with the addition of numerous common law tests which are discussed below.
Furthermore, we offer a number of relevant practical tips for utilising an expert witness to ensure that your experts evidence is not compromised.
Evidence Act 1995
The current rules for the admissibility of expert evidence require that the evidence be relevant to a fact in issue (s 55) and that the evidence has sufficient probative value (s 135). Critically, it must also satisfy section 79 of the Evidence Act.
Section 76 of the Evidence Act contains what is termed the ‘opinion rule’. The opinion rule states that:
“Evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed.”
Section 79 offers an exception to the opinion rule in the following terms:
“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.”
Therefore, before evidence can be admitted as expert evidence, three requirements must be satisfied:
- The witness giving the evidence must have a ‘specialised knowledge’;
- This specialised knowledge must be ‘based on training, study or experience’; and
- The opinion sought to be expressed by the witness must be one that is ‘wholly or substantially based on that (specialised) knowledge.
The opinion sought to be expressed by the witness must be one that is ‘wholly or substantially based on that (specialised) knowledge.
These matters are made somewhat more complex by the existence of the common law tests that are outlined below.
Criteria for Admissibility
The leading statement as to what a party is required to prove in order to successfully adduce expert evidence in proceedings in New South Wales is found in the judgement of Heydon JA (as his Honour then was) in Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at 743 at paragraph 85 (Makita).
Heydon JA’s criteria as to admissibility may be summarised into six key points:
- 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 demonstrates 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 witnesses 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, and so far as the opinion is based on assumed 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 opinion of an expert requires demonstration or examination of the scientific or other intellectual basis of the conclusions reached.
It is acknowledged that to date the Federal Court has not accepted Heydon JA’s criteria as outlined above as going towards the admissibility of evidence. However, the above must still be demonstrated if the Court is to attach any significant weight to the evidence of the expert witness.
Extra care must therefore be taken depending upon the forum in which you choose to commence your proceedings. You should therefore ensure that the correct strategy is implemented so that both your expert and any expert report meets the above criteria prior to any litigation.
The Experts Role
The Expert Witness Code of Conduct (the Code) found in Schedule 7 of the Uniform Civil Procedure Rules contains the rules which an expert must follow.
Perhaps most importantly is the explicit duty of the expert as contained in clause 2 of the Code, namely that:
- An expert witness has an overriding duty to assist the court impartially on matters relevant to the expert witness’s area of expertise.
- An expert witness’s paramount duty is to the court and not to any party to the proceedings (including the person retaining the expert witness).
- An expert witness is not an advocate for a party.
It is important that an experts’ opinion does not become tainted and that the expert remain impartial to the parties of the proceeding. The expert’s duty is at all times to the court and not to act as an advocate of a particular party. An expert must formulate their opinion based upon the evidence that is before them.
In R v Gordon Woods (2011) NSWCCA 258 a key expert opinion was rejected on appeal. It was found that the expert failed to act with an impartial duty to the court. Instead the expert took it upon himself to act as an advocate for the prosecution and hence the evidence provided by the expert was said to be “skewed”. Put simply, the expert was attempting to prove the defendant guilty rather than offer an unbiased expert opinion to the court.
Practical Tips for Engaging Experts
You should always proceed with caution in your dealings with experts. This is to ensure that the waiver of legal privilege does not occur, and also to ensure that the expert remains independent of the proceedings and avoids adverse inferences being drawn about the experts relationship to the proceedings.
In this respect, we recommend that the following be taken into account in all dealings with experts:
- Engage the expert on the assumption that all communication between legal advisers and the experts will become discoverable during litigation. This includes all documents provided to the experts, draft reports, expert’s notes, and notes of oral communications.
- In light of the above, written correspondence with the experts should be kept to a minimum. When written correspondence does occur, it should come directly from the legal adviser. Contact between the expert and the client should be kept to a minimum.
- Any changes to reports between draft and final form must be able to be explained by the expert. If an expert amends a report after a conference with legal advisers the court will draw adverse inferences in the case where adequate file notes of the conference are unable to be provided.
- Documentation that is to be provided to the expert to consider in forming an opinion must be carefully considered. If an expert relies on a document that attracts privilege in forming his opinion, privilege may be lost.
- Draft reports, or any other document, should not be forwarded to the legal adviser unless previously directed to do so by the legal adviser.
- When engaging an expert the legal adviser must provide a clear letter of instruction which contains a clear statement of facts and clearly sets out assumptions that the expert is to rely upon and the questions that expert is to address.
- If asking an expert to rely upon assumptions in formulating an opinion, the assumptions to be relied upon must be able to be independently proved to be admissible. It is the legal advisers duty to test that the assumptions relied upon by the expert are in fact able to be independently proved. The same is to be said for situations whereby the expert brings in additional evidence to formulate an opinion.
Commercial Litigation Lawyers Sydney at Pavuk Legal can assist you with a full range of legal services in respect to obtaining experts to provide evidence in a vast array of legal matters. We have extensive experience in managing expert witnesses to ensure that experts reports are admissible and relevant.
We have contacts that ensure we are able to obtain experts to consider your case and provide an opinion in an extensive range of legal matters.
In particular, Pavuk Legal specialises in the handling of insurance claims in which expert evidence often proves to be crucial in the successful receipt a benefit. Pavuk Legal has represented clients in a variety of insurance cases ranging from personal injury claims to highly contentious total and permanent disability claims.
For the full range of Legal Services that Pavuk Legal offers please go to: www.pavuklegal.com/services/
