High Court finds parties not bound by expert determination which contained manifest errors

In a recent decision, the High Court granted a claim for declaratory relief that parties were not bound by an expert determination which contained manifest errors, where the relevant clause in the underlying contract contained a carve-out for manifest error or fraud on the part of the expert: WH Holding Ltd v E20 Stadium LLP [2025] EWHC 140 (Comm).

While noting that what constitutes a manifest error will depend on the circumstances of a specific case, Paul Mitchell KC, sitting as a Deputy High Court Judge, concluded that the appropriate test was whether the error was "so obvious and obviously capable of affecting the determination as to admit of no difference of opinion". He also warned against evaluating errors by reference to pejorative language such as whether the expert has committed a "blunder" or "howler", which involve subjective judgment and may cast unfair aspersions on the expert's approach.

Applying this test to the errors identified, the judge found that these were indeed "manifest" and went to the heart of the expert's determination. Accordingly, the determination was not final and binding.

The judge also provided helpful comments as to what materials a court can consider when evaluating whether an expert's decision contained manifest errors. While, again, each case will turn on its facts, in circumstances where the parties had agreed that a reasoned decision might only be overturned on grounds of manifest error or fraud, it was appropriate for the examination to be fairly thorough, including in this case a review of the submissions made to the expert and the documents mentioned in them.

For more information, see this post on our Litigation Notes blog.