Expert witness

Being an expert witness

Expert witnesses are bound by different rules of evidence and codes of conduct depending on the court or tribunal in which they are appearing in. For example, the rules of expert evidence in tribunals are generally less onerous than those in supreme courts.

Some general rules that apply across the board for expert witnesses include:

1. The expert witness has a duty to assist the court or tribunal on matters within their area of expertise.
2. The expert witness should state the facts and assumptions relied upon in reaching their determination.
3. The expert witness cannot be an advocate for the party that engages them, meaning the evidence they provide must be impartial and unbiased (this extends to omitting evidence also).
4. The expert witness should indicate when a question or issue is not within the ambit of their expertise.

Architects should also bear in mind that, if they are giving expert evidence as an architect, they are also bound by the Architects Code of Conduct applying in the relevant jurisdiction.

With the breadth of law surrounding expert evidence in each jurisdiction, an expert witness who is not familiar with the rules of evidence or court procedures should seek guidance from the solicitor or counsel who has requested the expert to give evidence.

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Preparing an expert report

Before commencing work on a report, the expert should ensure that they are given access to all relevant documents and information. If there are uncertainties in the documents, then the expert should inform the solicitor or counsel who has requested the evidence. If the relevant documents or information is not provided in response to a request, the expert should detail that in their report.

In preparing the report, the expert should use techniques which are recognised by their profession as being sound. In particular, experts should:

1. Explain the field(s) of specialised knowledge in which they are an expert by reason of their training, study or experience, and on which the opinion is based.
2. Demonstrate that the specialised knowledge has been applied to the facts assumed or observed.
3. Give the basis and reasons for the opinion expressed in relation to each question to be answered in a way that allows the reader to understand and evaluate the conclusions reached, including by:
   a. stating what assumptions are relied upon and the basis for them
   b. noting any particular documents and information relied upon
   c. referring to relevant standards, tolerances and codes that relate to the issue in dispute
   d. detailing the basis for conclusions drawn
   e. providing any relevant supporting evidence (for example, photos or video or measurements) the expert considers necessary to support the findings.

During the course of preparing a report an expert may be required to consult with the solicitors or counsel who engaged them in order to ensure that the relevant rules of evidence have been complied with and that the report will be admissible and of assistance to the court.

So long as the opinion expressed remains the expert’s, and is not improperly influenced by the lawyers during that process, that is an acceptable process.

The expert should try to anticipate possible arguments in favour of the opposing party and to keep counsel advised accordingly. The conduct of the trial is in the hands of counsel but the expert witness has almost always been asked to participate because of expertise in the field of some of the issues involved.

Courts and tribunals generally have the power to direct the experts engaged by the parties to proceedings to confer, to endeavour to reach agreement on any matters in issue, and to prepare a joint report setting out matters upon which they agree and disagree. If an expert wishes to amend or qualify their initial report in some way as a result of that process, the expert should advise the solicitors or counsel accordingly.

Experts may also be involved in negotiations and settlement discussions involving solicitors or counsel.

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Oral evidence

On entering the witness box and before giving evidence, the expert may need to prove that they are qualified to give expert evidence on a particular topic by reciting the qualifications on which the claim of expertise is based. Having satisfied the court on this point, the expert witness will need to detail the facts upon which the opinion is based and give their opinion on those facts. Some facts will have been provided to the expert by others, and some will have been ascertained from his or her own investigations. The expert should clearly distinguish between those two categories, and indicate if they have been unable to verify any facts provided, so that the court is aware of that.

Like all witnesses, expert witnesses can be cross-examined in relation to the evidence they provide. Accordingly, it is important to prepare the report and evidence with due diligence and frankness. If an expert is not sure about an issue, they should qualify their opinion accordingly. It is critical that any witness listen carefully to the question, understand what information is being sought, and then give as direct an answer as possible. Generally speaking, the answer should be given concisely and firmly (although not impolitely).

Some general rules for appearing at legal proceedings in person are as follows:

• Be neatly and appropriately dressed and attend on time.
• Address the presiding officer accordingly.
• Do not get annoyed or impatient.
• Qualify an answer if necessary or refuse to reply to an improper question (subject to the view of the presiding officer who will provide guidance in those circumstances).

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Arbitration

Arbitration is a determinative dispute resolution process and is often favoured because the parties can choose how the proceedings will be conducted and adjudicated. This extends to rules of evidence and expert witnesses. Most arbitral proceedings will adopt standing court or tribunal rules but may, in some circumstances, adopt new or amended rules. Accordingly, it is prudent for expert witnesses to familiarise themselves with the relevant rules and when in doubt, seek advice from counsel.

For further information on arbitration, see Acumen note Negotiation and dispute resolution.

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