Walker actually has a reputation as an overly-emotional player. From http://www.draftexpress.com/profile/Bill-Walker-552/
"The one major concern that arose from this past weekend’s games is something that has always been an issue when talking about Walker: his emotions. It has been well documented that Walker is a fiery competitor, but also at times very unstable with how he handles himself on the court. The specific incident that triggered this response came when a minor altercation occurred between Walker and Brian Butch of Wisconsin in which Walker was pushed to the floor by Butch. While things didn’t escalate between the two players, Walker’s demeanor clearly changed after this, often clapping wildly on defense perhaps as a means of firing himself up even more. These issues can be a reason for concern for GM’s in today’s image conscious NBA."
Yeps. I didn't watch that particular episode, but Walker is clearly too fierce and emotional on the court, in a bad way. The kind of player who wants to score on his direct opponent after every time he scores on him or goes for some crazy shot-block attempt because he feels the team needs a stop. He can make some ill-advised plays on both sides of the court when things are not going well, including, I presume, throwing some elbows (not saying it was what happened here, I have no idea). I'm not worried about the image thing, he won't start punching refs or anything of that kind, but this is also, I'd say mostly, a problem from a coaches perspective and it must be corrected.
The only of correcting it is by practicing, playing though scrimmages. The veterans and the coaching staff will eventually find ways of humbling the kid and making him more poised and disciplined.
In general, this is a good thing. Guys are practicing hard, whit competitiveness, and, as the old saying states, only perfect practice makes perfection. You have to practice with the same desire and effort you play.