Interestingly, the tribunal found that Mr Prior had been unfairly dismissed because the length of the prison sentence was not sufficiently long to justify creating a frustration (viz. no reason for dismissal falling within section 98(1) of the Employment Relations Act 1996).
It should be noted that the Tribunal had adduced from all the facts found that “….. the [employer] had had difficulties with the Claimant and saw the prison sentence as an opportunity to terminate his employment, but unfortunately for them erroneously using, as a reason, frustration of contract.”
This case is interesting because the employers argued (and won on appeal) to reduce their exposure to costs by suggesting that the employee was contributory to his dismissal.
Contributory conduct is long established in two judgements. “The first of Brandon LJ in Nelson v British Broadcasting Corporation (No 2)  ICR 110, namely:
Hutchinson helps us in that it further clarifies that the fairness of the dismissal is not relevant to the question of a causative link between the dismissal and the conduct which is said to be blameworthy. In this respect the EAT agreed, the employee was part contributory and the EAT upheld the contributory reduction.