Honestly, I would make a beeline to the town office. (After discreetly removing my extension if unpermitted).
Because the electrical inspector/permit issuer needs to know about this. First, they need to know that this guy out there making messes, so to watch out for him.
And second, you have to ask if he filed for a permit for the work he did to your house. If he did pull a permit, then the inspector really dropped the ball on the inspection, and he needs to know that.
If he did not pull a permit, you're in a bad spot because you now have unpermitted work in your house. That could blow up in your face when you go to sell the house, at which point it will be much too late to seek recourse from the "electrician", and you will be left holding the bag.
That is why I would make this thing blow up now, while he can be held responsible for doing the job right. You want the job done right and you want the inspector to sign off on it. Honestly I think the inspector has the best chance of putting leverage on him.