I don't see a way that you /could/ tell on him, but if you could, I feel you should.
I don't hold with the mentality that you'd be "tatteling". You're fixing the situation and enforcing the rules. Something a lawyer should strive to do, if at all possible, in my opinion. Also, your selfish motives are perfectly justified. Why should you have to suffer for his lie? Or anyone else for that matter?
I don't believe in karma, so I feel that humanity has to be self policing. You want someone dealt with, you do it yourself. I don't know how you'd alert people to it subtly, but while this isn't quite intellectual dishonesty, it's damn close in my opinion, and should definitely be punished.