The Claimant was engaged by the Respondent as a consultant, and he contended that he made three protected disclosures to the effect that a major client had been overcharged, as a result of which he was subject to a number of detriments, including the termination of his consultancy agreement. The ET was concerned not with whether the Respondent did overcharge the client, but with what the Claimant reasonably believed; and the ET concluded that the Claimant did not have a reasonable belief that the disclosures were made in the public interest. The Claimant appealed on the grounds that the ET had misapplied the public interest test, and that the language used by the ET set a higher threshold to establish causation.

The EAT held that the ET erred in law in its analysis of whether the Claimant reasonably believed that he made the disclosures in the public interest, since it did not appear that the guidance in Chesterton Global Ltd v Nurmohamed [2018] ICR 731 had been taken into account. Also, the ET's determination that the disclosures "had little influence" was not the same as having had no material effect on the decision, so the ET had applied the wrong legal test and had erred in law in considering causation. Accordingly, the matter would be remitted to a fresh ET, to consider whether the disclosures were, in the reasonable belief of the Claimant, made in the public interest, and to determine whether any protected disclosures that might be made out were an effective cause of any of the detriments.