Yeah... I don't care what the guy in the audience said. If it was a threat or dangerous then the freaking mayor should call the baluff/police chief/sheriff who is going to be sitting in that room and let them deal with it.

If it's not an arrestable offense or something that would allow the mayor to eject the man from the meeting, he needs to act like a politician and ignore it in the moment. Threatening a member of the public during a city council meeting? He should be resigned immediately. He cannot continue to have the chance to wield the power of the office against a member of the public.