The thing is, people like Artest confuse self-defense with retaliation.
You get a cup of beer dumped on you and then beat the shit out of the person, you're acting in retaliation, not self-defense.
It's sort of analogous to if someone on the board called me an asshole, then I tracked him down and beat the shit out of him.
I thought it was indicative of the dumb conformist mentality of these jocks when Gilbert Arenas said something to the effect of (in defense of Jackson and O'Neal, I guess)"Hey, if someone is getting on your teammate, you gotta go help him out."
Dude, learn to think for yourself.