Expert determination and "manifest error"

In WH Holding Ltd v E20 Stadium LLP [2025] EWHC 140 (Comm); [2025] BLR 150 Mr Paul Mitchell KC, sitting as a Deputy High Court Judge, held that an expert appointed by the parties to determine an issue had made two errors in reaching his determination and that these errors amounted to a "manifest error" such that the determination reached by the expert was not final and binding on the parties. In order to constitute a "manifest error" it is not necessary to establish that the expert has made a "blunder" or a "howler". Rather, the test to be applied is whether the error made by the expert is so obvious and obviously capable of affecting the determination as to admit of no difference of opinion. On the facts the error found to have been made by the expert satisfied these requirements with the consequence that his determination was not final and binding on the parties.