The High Court has upheld a county court decision that an employer was not negligent or vicariously liable for the actions of an employee whose practical joke unintentionally caused injury to a contractor at work. It was held that it was expecting too much of an employer to devise and implement a health and safety policy, or other policy or site rules, which descend to the level of horseplay or the playing of practical jokes. It accepted that the contractor had previously made his supervisor aware that there were rising tensions between employees and contractors on-site. However, there was no foreseeable risk of injury as tensions were not so serious as to suggest the threat of violence or confrontation. Increased supervision to prevent horseplay, ill-discipline or malice was therefore not a reasonable step to expect this employer to have identified and taken.
Following the Supreme Court’s decision in Morrison Supermarkets plc v Various Claimants  UKSC 12, the court held that, although the incident happened in the workplace, the employer was not vicariously liable for the employee’s actions. Those actions were unconnected with any instruction given to the employee in connection with his work and did not in any way advance the purpose of his employer. The workplace merely provided the opportunity to carry out the prank, rather than it being within the employee’s work activities.