Quite to the contrary. Clarkson hitting the producer is actually pretty weak, not because of the physical altercation part, but because you already should have the authority as the boss and having to resort to violence shows that you don't have a solid grip on that authority.
Hitting your boss, though, that's pretty cool, let's admit that. And again if you were the boss and got hit by your subordinate, it's actually time to show why you are the boss, show that you have the character to raise above that and the ability to reinstate your authority without having to resort to external means (i.e. firing him) by simply keeping your cool, making fun of his punch etc (or better yet, dodging

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Either way, if we were to act, and not just pretend, like the job actually matters, then no-one should be automatically fired because of something that has nothing to do with the said job. The only time you should fire someone is when the conflict poses a real threat to the integrity of the team, or your ability to lead the team. Which shouldn't honestly be that often.