I'm confused...I'm not saying he doesn't "know code," but knowing code doesn't mean you know someone else's functions very well. Also, there's no Java in vBulletin, or in my hack. Theres a tiny bit of JavaScript, though (it's actually very, very different from Java, despite the name)...but there's hardly any of it at all. Are you saying that he doesn't know anything about JavaScript?
BTW: which script did he write? I'm sort of curious.