He will receive an form from the insurance company to investigate whether he will sue the third responsible party and recover the money. If not, he is not responsible for anything. Insureance company might directly sue the third party for the money based on the informationi he provides on the form. However, if he gets money from the third party, then he is responsible to pay insurance back. But in this case, he can ask an discount, and most of time the insurance company would be happy to give him one, since they could get some money back without any effort.