The correct response occurred - assuming he said the bomb word.

Say you are on a street, you tell a policeman, you have a gun in your jacket. Then you say it was a joke. Do you think they'll just let you go on your way without doing anything, look inside your jacket to see if you were joking, or ask you a few questions. I assume the last one, to say the least.

So rather than hold up the flight, they removed the passenger to ask him a few questions - which is what happened. It also just happens that saying you have a bomb is against the law. So he was charged. If it wasn't against the law, he would have been released.

Bottom line - do anything threatening to anyone in authority, anywhere, and expect to at least have your bluff called, and be inconvenienced. And before you say the law is wrong, think about this - it's a big ask to have an FA make a judgement call based on whether they perceive a threat to be real or not. I'd rather those decisions be made by people with more experience - like law enforement officers - who are specifically trained to evaluate threats.