Yes, it's a serious charge and one that might well keep him out of BYU. And if he is convicted, he shouldn't be at BYU.
My very simple point, which nobody seems capable of understanding, is that we shouldn't make a lot of assumptions about a person based on a single incident. If this type of thing were routine with him, he would have gotten caught a long time ago.
If he were some type of troublemaker, he would have been getting into lots of trouble all through school, would probably would already have an arrest record, etc.