My theory is that Cassidy might have been capable of blowing up the bus, (even though he told Lamb that he went to the garage with his dad once and never really met Curly Moran,) but that he lied to Veronica about the rape, hoping that she'd shoot him. When he says, "And Dick thinks I'm still a virgin," he wasn't talking about Veronica at all . . . but about Woody. When you're a guy, there's really only way you get chlymidia from another guy. As for Veronica, I think she got it from Duncan or maybe from Logan.