The Claimant, who is employed by the Respondent, made a total of 18 protected disclosures and he claimed that, as a result of having made those disclosures, he was subjected to a number of detriments by the Respondent. The ET rejected his claim, concluding that the Claimant had not established that any of those detriments were because he had made those disclosures. The Respondent made an application for costs, on grounds including that the allegations as to detriment (or a number of them) made by the Claimant were so weak as to have no reasonable prospects of success and the Claimant acted unreasonably in pursuing them. In its costs judgment, the ET concluded that the Claimant had presented a case which had no reasonable prospect of success and acted unreasonably in pursuing such a case over a very lengthy hearing; accordingly, it exercised its discretion and decided that the Claimant should be liable for the Respondent's costs (estimated to be in the region of £170,000). The Claimant appealed against the ET's costs judgment on the grounds of perversity.

The EAT held that the high threshold for a perversity challenge had not been crossed and the appeal would be dismissed.