I find it a hard stretch that not one of them would have returned a call out of courtesy, if nothing else, if they didn't have reason to believe that Brian had done something they would need to be very careful about.
As a parent, I believe I'd have called my kid's bluff if he came back solo, told me whatever, even said "please don't talk to them/bad breakup," but then I started getting contacted by his gf's family.
At a minimum - hey, Bri, this is rude. I'm not doing this to these people. Tell me what's what or I'm getting on the phone with them right nah.
5 minutes later: where the HECK is that idiot attorney's number? Geez, I hate that guy, but we've got no choice at this point. Brian, go to your room. Now!