Possible violation of permanent restraining order

I think it's extremely unlikely that he will be found in violation if he is inside the house when she is around;  if he needs to come in or go out when she is in town, I'd suggest that you (or another friend) go outside to make sure that "the coast is clear" first.

Most courts take a common-sense approach to this sort of thing.  For example, a no-contact order isn't violated by finding yourself, in your car, stopped at a red light alongside the car of someone with an order against you, as long as it was by accident. But, in that situation, I have seen the restrained person's decision to roll down the window, on the side toward the other person, treated as a "threat of contact" and therefore a violation.

Another good idea would be for your boyfriend to have a lawyer on board ahead of time, with all the background, so that he or she can jump right in if there's an incident or an arrest.