The simple fact he is outright seeking to exploit rules and go balls-to-the-wall means he isn't going to be a good addition to any group synergy. It's going to be all about him or he isn't happy, the other players...and you, be damned.

Carrying on without him is about the only recourse for you that will work really. Untill you two have a dialog about whats really going on, it will not get better. If he is back in the game he will just snipe snipe snipe about it and do his passive-agressive thing. You didn't make the game FOR HIM, you made the game so he could be ONE of the PCs.

All in all, this all could have been averted by reviewing the characters before the game starts, even better you could have laid some ground-rules before-hand instead of throwing it against the wall and seeing what happened (if thats what you did.)

No sense in him ruining it for everyone.