Sounds to me as if the student was really out of it and acting EXTREMELY stupid and reckless. He had taken the baton from the cop and was beating him with it? Really? Even if it wasn't a serious beating and basically just teasing, and even when you're pissdrunk or high as **** on whatever, that's absolutely moronic.
Then again, one or two shots to the legs should have been enough for the police officer to stop an unarmed student from charging him. Maybe he was panicking at that moment, but this is no excuse for shooting him in the head and chest.
Both made mistakes here. If what the article says is true, then the cop is far from being the only one to blame.