WRITTEN BY Alan Bradbury
Expert witnesses are special because they are allowed to give evidence about their opinion and not only about matters of fact.
The usual rule is that evidence given in Court must relate to matters of fact: what a witness did, saw or heard; and not matters of opinion: what the witness thought about what they did, saw or heard.
It is the judge’s role to listen to the evidence of what people did, saw or heard (i.e. ‘facts’) and draw inferences from those facts to form an opinion about what actually happened.
Expert opinion is an exception to the usual rule that allows a person who has specialised knowledge based on the person’s training, study or experience to give opinion evidence in Court proceedings that is based on that person’s expert knowledge.
The Evidence Act provides that, if a person has specialised knowledge based on the person’s training, study or experience, they are allowed to give opinion evidence that is wholly or substantially based on that knowledge. However, there are some rules about when and how this will be allowed. These are:
1. Relevance or helpfulness test
This is fundamental – evidence in any court proceedings is only admissible if it is relevant. Unless the expert evidence is relevant and will help the Court make its decision, the evidence will not be allowed.
2. Specialised knowledge test
This has two elements:
3. Qualifications test
The witness must be an expert in their field and must have acquired specialised knowledge on the topic based on their training, study or experience. Academic qualifications and experience usually go together – simply holding an academic qualification with no real experience would not be accepted by most of us as qualifying a person as an expert. However, sometimes people are recognised as experts even though they do not have the relevant academic qualifications if they have significant practical experience. For an example of this in a local government context, see our article here.
4. Basis test
Again there are two aspects to this test:
The key instruments listed at the top of this Guide contain detailed requirements about the preparation and giving of expert evidence in the Land and Environment Court of NSW (the Court). The most important thing to be aware of is that the overarching duty of an expert witness is to the Court, not to any particular party.
The Court may require ‘competing’ experts to discuss their views to try and narrow or resolve the expert issues in dispute. This is called joint conferencing. The Expert Witness Code of Conduct sets out requirements in relation to the joint conferencing of experts. The Code currently requires the experts:
The Code requires each expert witness to exercise his or her independent judgment in relation to every conference in which they participate and in relation to the preparation of each expert witness report. It provides that the expert must not act on any instruction or request to withhold or avoid agreement.
The Court’s Practice Notes provide that legal representatives are not to be involved in the preparation of expert reports and are not to attend joint conferences of experts without leave of the Court. The legal representatives should however ensure that experts are familiar with the relevant parts of the key instruments listed above.
Where a dispute arises between the experts in the preparation of their joint report it is possible to seek directions from the Court to resolve the dispute – Landco (NSW) P/L v Camden Council  NSWLEC 86.
The Court’s Joint Expert Reports Policy provides that an expert report should:
1. Be prepared – thorough preparation is the key to being a credible and confident expert witness:
2. Take care in writing your expert report:
3. Be punctual and ready – Make yourself feel comfortable about the exercise and don’t arrive at Court feeling rushed. Talk to your party’s lawyers beforehand about how your evidence will be taken and make sure you are ready for what is coming. Even little things like being asked whether you will give your evidence on oath or affirmation can throw you if you are not expecting to be asked – especially if you are already feeling a little nervous. Have any papers you need ready to take with you into the witness box. Make sure documents are stapled, or logically organised in a folder, and paginated so you can find and refer to them easily.
4. Prepare thoroughly – make sure you have thoroughly read your individual and any joint report. There is nothing more embarrassing than finding that the other side’s lawyer has read something to you from your own report that contradicts your argument.
5. Make sure you understand each question before answering it – guessing what the question was can get you into trouble. There is nothing wrong with asking a lawyer to repeat a question.
6. Answer the question that was asked as directly, concisely, honestly and courteously as you can. Don’t try to work out where the questioning is going or answer the question that you think should have been asked – but wasn’t. Take your time – If you need to refer to your papers to be able to answer a question, say so. Don’t fall into the trap of trying to appear knowledgeable by answering too quickly. If you need a moment to consider your answer – take it.
7. Direct your answers to the judge/commissioner – they will be the one who will decide the case, not the lawyers asking you questions. Also, don’t look to your own party’s lawyer for approval when answering questions from the other side. And stay interested in what’s being said especially during ‘hot tubbing’ when questions are being directed to another expert – looking bored or distracted will not reflect well on you.
8. Make necessary and appropriate concessions – your objectivity is essential to the credibility and reliability of your expert evidence. This will not be lost by forcefully defending your opinion but it may be compromised if you are unwilling to give genuine consideration to other points of view.
9. Don’t lose sight of your primary obligation to assist the Court – it is very easy to fall into the trap of being an advocate for the party who engaged you. Your role is to provide an impartial opinion to assist the Court make an informed and fair decision. Don’t undermine your credibility by starting to argue for your client’s position.
10. Finally, don’t engage in personal exchanges with the other side’s lawyer – you will nearly always come off second best!
 We acknowledge the helpful assistance derived from the following articles in the preparation of these tips:
‘The Art of Giving Expert Evidence’ by Gerry Lagerberg published in The Lawyer 10 April 2000
‘Medical Expert Witnesses: Tips and Traps When Giving Evidence’ by Harry McCay and Dr Walid Jammal, Avant Mutual, 20 July 2017.
The content contained in this Essential Guide is, of course, general commentary only. It is not legal advice. Readers should contact us and receive our specific advice on the particular situation that concerns them.
Please note that the law detailed in this Essential Guide is correct as at 26 April 2018.
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