Have to agree with Herc-u-lease point here, living on an overseas base at the moment, and the recent (military) visitors have broken into the pool and defecated on two occasions and even if only 3 of them did that you can be sure that the rest peed in the pool. They have started fights with the local kids on the base, sunbathed naked, stripped off on the family beaches and generally caused havoc. And all that is on their own door step so to speak. I am not tarring your son with that brush but in a group people have a strength that they do not normally possess as individuals. That is exactly what we are looking for when they are fighting for Queen and Country (and their mates) but you can see why it doesn't translate well into normal life.
I am merely stating examples to illustrate a point that sober or not groups of young people tend to think that they can do what they want where they want without reproach. Back to my original point before you jumped down my throat......2 sides to every story.