LEGALLY he did nothing wrong except for the U turn. Basically he is at the mercy of the student code that NOVA has for having a firearm on campus. The maximum that could happen would be that NOVA expels him. I would read the code that NOVA has on firearms and see how to get around it. If that fails, I would plead to them that you forgot that it was in your car or something. Make sure they know that it was an accident/mistake and suck up to them. Hopefully they aren't anti and have a heart.
Maybe try to say that he made the U turn trying to leave campus as he suddenly realized that he was carrying on campus. (I would go with this personally)