An expert’s primary duty is to the Court. Not the interests of their client or who is paying their fee. Sound expert evidence is fundamental to upholding the rule of law and help in the proper administration of justice. Consideration of case law, and legislation (the Rules of the Superior Courts) are helpful to properly understand the role and duties of experts in litigation disputes.

The classic statement of the duties of experts is set out by Mr. Justice Cresswell in the Ikarian Reefer case National Justice Compania Naviera SA v Prudential Assurance Company Ltd (Ikarian Reefer, 1993).  In short, expert witnesses were held to provide unbiased opinion and independent assistance to the Court in relation to matters clearly within their expertise.

The Ikarian Reefer principles have been regularly cited with approval in the Irish superior courts. Most recently in Duffy v McGee [2022] IECA 254 by Noonan J. who reiterated the following principles:

“The overriding duty of the expert is owed to the court and includes the duty to provide an objective opinion”.

Noonan J. observed that: “It is unfortunately commonplace for experts to succumb to the natural tendency to put the interests of their own clients first, unconsciously or otherwise.” 

Collins J. in the same case summed it up best when he expressed a view that: “The most significant concern about expert evidence relates to issues of objectivity, impartiality, and independence.” 

Put bluntly, an expert must not be a ‘hired gun’. Someone perceived by their instructing solicitors to be favorable to their case. 

The Superior Court Rules, Order 39, rule 57(1) also provides guidance on the role of expert witnesses:

“It is the duty of an expert to assist the court as to matters within his or her field of expertise. This duty overrides any obligation to any party paying the fee of the expert.

In summary, the acid test for any expert witness is that their evidence should be objective, impartial, independent, and unbiased. Most of all, it must clearly be within the expert’s area of expertise. The expert must therefore be careful not to stray outside their area of expertise. If they do, their evidence may be deemed inadmissible, and/or the expert may ultimately lose significant credibility before the Court.