KG is pretty intense is practice, maybe too much so. He's punched at least two of his teammates in the past (Wally and Rick Rickert). Usually, though, these things don't amount to anything; didn't Powe and BBD get into it once last year at practice?
In terms of Walker, I agree, it's good that he didn't back down. It shows he's not intimidated to be on this stage. (Let's hope, of course, that the elbows were completely accidental, as I'm sure they were.)