there is a chance he could be done for taking witout concent and no insurance possable 6 points and a fine,this will affect further insurance quotes for him.Dont you say he had your permission as you could be done for aiding and abeting in the offence.He cant be done for theft of the car as the term theft ,is to permantly deprive the owner of the car,he did not intend this so he cant be done for theft.but takeing without owners concent is an offence in its self.We all have to pay insurance as you do,sory i have no sympathy for him,what if he had an accident you and others would have a job getting paid out on insurance,was he bothered about what would happen to you if he had an accident and badly damaged your car.you would be without a car and have to pay a lot of money out.