Heckling is one thing, throwing things is another.
He should have shown more restraint, but I'm not Ron Artest, I don't know how he views things. I can say that I probably would have done the same thing.
Celebrities and athletes put up with a lot, it's part of the deal, but sometimes they lose it. The price of celebrity can be very high sometimes, look at Princess Di who isn't here anymore because she was a celebrity and the media couldn't leave her alone.
He has to face the consequences of his actions and he is doing so. It's case closed I guess.