In order to succeed in a claim of unfair dismissal, a claimant has to show that the dismissal was outside a range of reasonable responses to a given situation. It is not open to an employment tribunal to decide that, because it would not have dismissed for the same reason, the dismissal was unfair, provided the decision was not outside what would ordinarily be determined as reasonable.
This contrasts with discrimination arising in consequence of disability under s.15 Equality Act 2010. Under s.15, as long as it can be shown that the employer had knowledge of the disability, it doesn’t matter whether it also knew (or ought reasonably to have known) that something (misconduct, poor performance etc.) was a consequence of it. If the employee suffers a detriment because of that ‘something’ then the employer has to show that its actions were a proportionate means of achieving a legitimate aim, failing which it will be guilty of s.15 discrimination. Whether something is a proportionate means of achieving a legitimate aim is an objective test and therefore permits the employment tribunal to make its own assessment.
This distinction is illustrated in the Court of Appeal judgment in City of York Council v Grosset. In this case, Mr Grosset was a teacher. He had cystic fibrosis, which his employer was aware of. He was dismissed for gross misconduct as a consequence of his decision to show an 18-rated film to vulnerable adolescents. He brought a number of claims, including unfair dismissal and a s.15 discrimination claim alleging that the dismissal was unfavourable treatment because of something arising in consequence of his disability. His unfair dismissal claim failed but his s.15 claim succeeded.
Mr Grosset had been subjected to an increased workload and it was held that, in light of his disability, this amounted to unfavourable treatment of itself. This increased workload increased the stress he was under which, in turn, exacerbated his cystic fibrosis, which then further increased the stress he was suffering. It was found that it was the increased stress (a consequence of his disability) which led him to make the error of judgment which, ultimately, led to his dismissal. Whilst the school argued that it was proportionate to dismiss him because of the legitimate aim of safeguarding students, the tribunal disagreed. It was accepted that there was a legitimate aim, but was held that a proportionate means of achieving that aim, given Mr Grosset’s previously unblemished disciplinary record, would have been to issue him with a final written warning.