The irony of the law. When the Brit threatened to beat up the Sink, the Sink should have called police immediately. Police could arrest the Brit under criminal intimidation and charge him for the Sink. From the report, I suspect that the Sink dared the Brit to carry out his threat. But when the blow actually came, the case became VCH and police wouldn't arrest the Brit anymore and the Sink would have to file his own magistrate complaint and fight his own case. If the Brit was just a tourist, he could just go back to Britain. There's nothing the Sink could do about him. Had it been a police case, police could insist bail bond, impound passport and even arrest warrant depending on the degree of criminal intimation.
A famous example of criminal intimidation case was that of James Gomez wagging a finger at an election officer threatening her of consequences. ED called police. JG was stopped from leaving Singapore (to his workplace in Sweden) and had to report to police to be grilled over a few days of interrogation and got away with a warning. He wasn't actually officially arrested, but if he failed to co-operate to report and record statements, the next would surely be an arrest warrant. However, it was fortunate that JG didn't actually touch the election officer. For it wouldn't be simple VCH in that case, it'd be assaulting public servant; arrest straightaway, no need to give face.