He might be. That's the hope lol. If you contact his boss about it might get him in trouble which he deserves for rejecting everyone for no reason.
I think in this case if he is not associated with a university, and not offering work on behalf of his employer, it is best to utilize the tools that you do have. Submit a bad review to TO and anyother forum you have at your disposal to warn other workers about him. Those who are wise enough will see that he is not a safe requester and that is pretty much the extent of what we can do. It sucks, and it is not necessarily fair, but contacting his employer who is not associated with his affairs outside of work opens you up to all sorts of implications. You could be considered one who is harrassing him, depending on the state he lives in and you live in there could be laws that protect him (not saying it is right) because you could be viewed as someone who is trying to collect a debt. Just protect yourself first is all.