I think USBC did everything it *could* do to determine whether these two were credible or not. The first one was administratively rejected as stated earlier in the post. I don't believe there's ever been a meeting between a proclaimed honor score bowler and the USBC and each set of attorneys. Both Mushtare and his witnesses were interviewed, and by current rules, there was no reason to reject the claim.
The problem is the rules that allowed prebowled honor scores to begin with (Remember the 900 prebowled in a different center during Cosmic bowling?). I don't see how USBC could have rejected the scores and not faced a huge lawsuit. And as much as everyone hates that these scores were recognized, I think they'd hate the idea of paying lawyers for a prolonged legal battle.