It happened in Denver Colorado to radio host Peter Boyles. He (allegedly) not only got violent with his producer, he did it in front of a television crew.
I have no knowledge of the situation at all, but I'm 100% behind the producer on this one. Anyone who does that to his producer with a television crew present has probably done worse when they aren't.
I saw it happen once to a friend of mine back in the early days of radio producers. Nothing happened to the host who did it. I don't think management even spoke to him about it. I've heard of at least two other incidents involving other radio producers since then (second hand), and nothing happened to those hosts either.
Makes me wonder if Peter Boyles just had lousy ratings and the bosses were looking for an excuse to fire him.