Often, when a dispute arises (and depending on the facts of the case), an expert report will be sought. This is a report, drafted by an expert witness, which sets out their opinion on the facts based on their own experience and expertise. This can be a useful tool in negotiations and mediations and, where court proceedings have been raised, can assist a court in reaching a determination.

What is an expert witness?

An expert witness is an individual who is a specialist in the matter in dispute (or a particular element of the matter in dispute) and an expert in their field. This could be an IT expert, instructed to speak to the metadata of a particular document in order to determine its integrity or a property surveyor, instructed to determine whether works have been properly carried out in a potential professional negligence case.

What is the role of an expert witness?

The role of an expert witness is to set out a professional opinion. This can be done in a number of ways – the party instructing the expert may have a face-to-face consultation with the expert in order to discuss the case, the expert may produce a report setting out the facts of the case and their opinion, the expert might appear in court to give evidence based upon their opinion, or this may be done by way of a combination of all three methods.

The opinion of an expert witness can be particularly useful in court proceedings. While judges are very experienced in the law, they cannot be expected to be experts on the particular subject matter of every case that comes before them. A report from an experienced expert can clarify the facts for a judge and can assist him or her in making a decision. Where each party to a dispute has instructed their own expert, the judge will generally consider the evidence given by each and determine which he or she prefers, based on the reliability and credibility of the respective experts.

What duties and obligations does an expert witness have?

The primary duty of an expert witness is to the court. This means that the expert must provide their unbiased opinion as an independent expert insofar as they are able. The instruction should be kept confidential, unless otherwise agreed with the instructing party. The expert should ensure that they adhere to any deadlines imposed by the court and that they are not subject to any conflicts of interest. The duty to act with reasonable skill and care also applies to an individual acting as an expert in a dispute.

An expert should be honest and know the limits of their own expertise – if something is asked of an expert which is beyond their particular area of expertise or which they are uncomfortable with, they should say so. It is important to note that, while an expert is usually instructed by a party in a dispute (rather than by the court), they are not obligated to set out an opinion in favour of that party and indeed their evidence should not be influenced by the interests of the instructing party.