I can't wait for that episode either.
I think that sometimes people don't want to see that someone was doing something incredibly wrong, I'm not saying that guy deserved to die, but at the same time, he was beating someone, he was involved in other beatings that night that resulted in someone dying, and he was about to throw a huge rock through the windshield at that moment Greg had to do something.
Greg was protecting himself, I think the reality that the guy that died wasn't all that wonderful, wasn't all that good will be hard to see for them. I'm sorry, but anyone who beats innocent people for the fun of it to the point where they are hospitalized and maybe die is not a good person. He wasn't standing to the side, he didn't run away, he was enjoying himself, and that alone is just sad.