I guess it really depends how much damage was done to your car wether its worth not reporting and paying for the fix yourself or if the fine and repercussions of not having a license will be less costly, in PA by law you aren't even supposed to call the cops in an accident unless at least one of the cars cannot drive away
You can let him go and live with your busted up car and no pay, or you can report it to your insurance, get payoff, and then get in trouble for the liscence. The first option is likely going to cost a lot more.
Sue him. If he has the best lawyer in the world he could get off on the fact that you don't have a valid license, but that's not likely. Just to start the berating. Why didn't you renew your license you lazy bum.