Eastern Magistracy said Samuel Bickett caused the officer multiple injuries by hitting his hand and stepping on his stomach, and the court would not tolerate such violent behaviour that seriously threatened public order.
Magistrate Arthur Lam added that the attack in December 2019 could have led to a bigger commotion as it took place at the busy Causeway Bay MTR station.
The court had earlier heard that the 37-year-old American corporate lawyer also tried to snatch the officer’s baton.
In convicting Bickett, the court had earlier rejected his defense that he heard the officer denying he was a policeman, and so he tried to subdue him for fear that he might attack other commuters.
The magistrate had said it was understandable for the officer to deny it when he was asked whether he was a “popo” – a “disrespectful reference” to the police – and noted he did identify himself as a police officer several times.
The incident happened three months after police officers were given approval to carry batons during off-hours at the height of anti-government protests.
The officer had said that before he was attacked, he had been using his baton to try to subdue another man, who he said had jumped over MTR ticket gates and escaped.