You wouldn't expect a Court of Appeal judgment about Michael Barrymore's claim for false imprisonment following his arrest after the death of Stuart Lubbock at a party held at Mr Barrymore's house to be relevant to employment law, but it might be.
The appeal concerned quantum. It was conceded Mr Barrymore's arrest was unlawful as the arresting officer was unaware of the facts he needed to know to enable him to have the reasonable suspicion necessary to lawfully arrest Mr Barrymore. Therefore his detention amounted to false imprisonment.
No other officer on the scene had those facts at their fingertips either, so if the arresting officer hadn't arrested him but one of the others present had, it would still have been unlawful and false imprisonment. There were officers who could have made a lawful arrest but they weren't on the scene at the time and they hadn't passed on their knowledge.
This enabled Mr Barrymore to bring a claim for £2.4m in damages for his alleged loss of earnings resulting from the damage caused to his career consequent upon his arrest.
The High Court held that had the arresting officer not arrested him he would have been arrested unlawfully by another officer present
How is this relevant to employment law? The answer lies in Polkey. The CA judgment is about the correct counterfactual to set up following recognition of unlawfulness. The High Court Judge looked at what would have happened if the arresting officer had not acted unlawfully and he concluded that another officer would have acted unlawfully, hence substantial damages were due.
But the appropriate counterfactual was not what would have happened in the absence of the unlawful behaviour, but what would have happened had it been appreciated what the law required.
The answer was either that (a) the arresting officer would have been given the facts prior to arrest to enable him to lawfully effect the arrest, or (b) an officer with appropriate information would have made the arrest.
Polkey is often similarly misunderstood, with parties looking at what the employer would have done if they'd not made the procedural error rather than looking at what would have happened had the correct procedure been applied.
This is an abridged version of a twitter thread produced by Jason Braier from Field Court Chambers.