I know that when a friend of ours died in his apartment, his roommate (a friend, but not a super close one) told us, and my husband had the unenviable task of calling his mother and sister to tell them what he'd heard. He told them to verify with the police department, but it was a case of the police having brought the ID to the friend's apartment and told the roommate that he'd been found, so it was pretty definite. We weren't sure why the police didn't notify the family, but it had also been quite a few hours after the death. Possibly since he was no longer a minor it wasn't so easy to figure out who the family were.
I don't really blame the guys too much, they probably assumed that the police notifies family right away (I know I always thought the police did, but sometimes maybe it takes a while for them to track the family down). And the family doesn't have the *only* claim on the guy, his friends do as well. Plus, they're all teenagers, they probably think they're much closer to each other than they are to the family.