How is that a huge problem? A stupid mistake by a teeenager, I have two at my house and they make dumb decisions every day. I can't see this being a compliance problem like the mom bought them a stuff as a boooster, actually that would probably be better.
As far as I know, the NCAA compliance rules don't make an exception for reporting a violation just because a dumb teenager took his mom's credit card and bought stuff for athletes. If it turns out that is what happened, hopfully his mom is not considered a booster or doesn't have some other kind of relationship with the university.