Expert determination and "manifest error"

The Court of Appeal in WH Holding Ltd v London Stadium LLP (formerly E20 Stadium LLP) [2026] EWCA Civ 153 has allowed an appeal from the decision of Mr Paul Mitchell KC (on which see our May 2025 issue, pp 7-10) and held that an expert appointed by the parties to determine a dispute between them had not made a "manifest error" in reaching his conclusion. The present case acts as a reminder of the fact that it is no easy task to challenge the decision of an expert on the ground of "manifest error" and this should be taken into account by parties when deciding whether or not to agree to expert determination.