I get that it may feel a little weird (or even very weird). What's even weirder to me is that he's so obsessed over what others think. Here's a woman he obviously thinks is gorgeous and possibly is the one who can make him happy, but is willing to throw all that away because of what others will think/say??? Yea, very weird. On the other hand, if he actually suspects that they might be somehow related, get DNA tested right away. Don't just ghost on her over something your roommate said
It does sound a little shallow. He tried to act like calling a radio station was bunk, but she had a good burn. AND, he ghosted! Like, moral high ground lessons from a turd, hard pass.