Systech Law

Role of the Expert and its duty of loyalty

by Tom Allen, Global Managing Partner, Systech Law

The recent case of Secretariat v A Company has shone light on the duty of the expert witness and the issue of conflicts of interest, but has it raised more questions than answers?

Reliance on expert witnesses in construction disputes is as prevalent as ever. It is precisely because of this that the role of the expert and their duty to the court or tribunal is so important.

The overriding duty of any expert is to assist the court in making its decision. This much is clear.

But what other objectives or obligations does an expert owe and to whom?

In the case of A v B[1] , Mrs Justice O’Farrell determined that, in addition to its duty to the Court, an expert owed a fiduciary duty to its client. The circumstances of the case were that an expert consulting firm sought to provide expert services to one party whilst at the same time being engaged by the other party in a similar capacity on a related arbitration. The firm was restrained in doing so on the basis that it owed a fiduciary duty of loyalty to the claimant.

The matter was appealed and as recently reported in Secretariat v A Company[2], the Court of Appeal offered a slightly different view whilst ultimately concluding upon the same outcome.

Rather than identifying a fiduciary duty of loyalty, Lord Justice Coulson concluded that such a view was unnecessary given the contractual terms of engagement that set out the firm’s duties in respect of conflicts of interest. Whilst not ruling out that such a duty exists, the court were hesitant to apply the position as simply as had been stated in the High Court.

"Whilst not ruling out that such a duty exists, the court were hesitant to apply the position as simply as had been stated the High Court."

Has this changed anything?

Well, the overriding duty is unchanged and nor was it ever in question. An expert’s primary obligation is to the Court.

It is also clear that an expert does, and is fully expected to, hold a parallel duty towards its client[3]. Whether that exists only as a matter of contract remains open for debate.

The reasoning and observations offered in the judgment provide additional guidance in respect of the role of an expert and, more specifically, the identification of conflicts in expert engagements.

The Court acknowledged that the duties of loyalty would depend upon the terms under which an expert is retained. In this particular instance, it was noted by the Court that the consulting firm’s contractual obligations surrounding conflict of interest were expressly stated as being applicable to any of its group companies also.

"The Court acknowledged that the duties of loyalty would depend upon the terms in which an expert is retained. "

Key considerations

The Court’s findings in this matter serve as a reminder to carefully consider the terms upon which an expert is engaged. Whilst great attention is often given to the bespoke instructions for which their expertise is sought, the standard terms shouldn’t be overlooked.

Any instructions must also reflect the role being undertaken. If that role changes, the terms and instructions should be amended and freshly agreed.

It is safe to assume that any breach of the conflict obligations in this case was not intentional. In fact, the Court even acknowledged that conflicts of interest are not always straightforward and can be a matter of degree, not least were there are different services offered by a firm in different locations across different group companies.

Nevertheless, to avoid any embarrassment and undue disruption to the legal process, it is a matter that must not be overlooked. Not for the first time, the devil is in the detail.

For further information on the role of the expert and conflicts of interests helpful guidance can be found at the following:

Civil Procedure Rules – Part 35

RICS – Surveyors Acting as Expert Witnesses, 4th Edition

IBA Rules on the Taking of Evidence in International Arbitration


[1] [2020] EWHC 809 (TCC)

[2] [2021] EWCA Civ 6

[3] Jones v Kaney [2010] EWHC 61 (QB)

"Not for the first time, the devil is in the detail."