It's sad to me that he would be discounted if he was actually drinking at the party. To me, it doesn't matter if he was a so-called partier. A lot of college students are. It wouldn't minimize his parent's pain. I seriously doubt that his being drunk would make any difference to them. I know it would make me very upset if people did this to one of my boys.
Drinking at a party wouldn't make it any less likely that something could have happened to him.
People are just so quick to judge.