EXP v Barker: The legal cost of a conflicted expert witness

A recent Court of Appeal decision in England and Wales acts as a reminder of the importance of ensuring that your instructed expert is independent and  that any conflicts of interests are addressed at the outset.  

The Northern Ireland Court Practice Direction No 1 of 2015 outlines the duty of expert witnesses in the Commercial Court and requires that a signed Expert’s Declaration is appended to their report. In doing so the Expert declares that in providing written reports and giving evidence is to help the Court, and that this duty overrides any obligation to the party by whom they are engaged or the person who has paid or is liable to pay them.

In the recent medical negligence case of EXP v Barker [2017] EWCA Civ 63 before the Court of Appeal it emerged during cross-examination that the Defendant’s expert had a “lengthy and extensive” relationship with the Defendant. This included training the defendant and collaborating on academic publications. The Plaintiff’s made an application to exclude the Defendant’s expert’s evidence however the trial judge decided to admit the experts evidence but went on to say that when accessing the weight which should be given to the evidence that he “must bear powerfully in mind…[the experts] independence and objectivity” in the case.

The Defendant advanced an appeal on five points, three of which related to the weight which the trial judge had given to the Defendant’s expert’s evidence. Irwin LJ who gave the leading judgment in the Court of Appeal found that the trial judge was fully entitled to take that view, and indeed, if he had decided to exclude the evidence entirely, it would have been a proper decision. He added that:

our adversarial system depends heavily on the independence of expert witnesses, on the primacy of their duty to the Court over any other loyalty or obligation, and on the rigour with which experts make known any associations or loyalties which might give rise to a conflict”.

The role of expert evidence is an imperative part in both quantum and liability evidence in Commercial Court matters. Mr Justice Weatherup has specified in the Practice Direction that experts who fail to comply with the Rules of the Court or the Practice Direction may be subject to sanction. These include that the party who instructed the expert may be debarred from relying upon their evidence and that the expert themselves may be held responsible for wasted costs and have some or all fees disallowed.

While decisions of the Court of Appeal in England and Wales are not binding in this jurisdiction it is practice that they are persuasive authority to the Northern Irish courts. This case, when read with the Practice Direction, is a stark reminder to experts and practitioners of the importance of impartiality and independence of experts who are involved in providing services to the Court.

Therefore it is imperative that conflict of interests are addressed at the outset and their overriding duty of an expert to the court made clear in their letter of instruction. This is even more so a factor to be considered at the outset of a case in Northern Ireland given the size of the jurisdiction and if there are any conflicts that these are disclosed as soon as practical, as failure to do so, could be detrimental to a party’s case.





While great care has been taken in the preparation of the content of this article, it does not purport to be a comprehensive statement of the relevant law and full professional advice should be taken before any action is taken in reliance on any item covered.