KVN was held accountable for mistakes he made before he even enrolled at BYU or signed anything. He spent a year showing Bronco that he had learned from his mistakes before he was allowed to join the team. This is much different than missing a little practice time.
Don't get me wrong, I am not minimizing the mistakes that KVN made. Getting a DUI is egregious. But he manned up and showed he could stay out of trouble before given the priviledge of becoming a part of the BYU team.