Here in CA the police will not usually even come if there are no injuries. Did the other guy hit your sons car as he backed out of a space? If so by hitting the middle of the car I would think it was his fault. If he hit your ds car he should have already contacted his insurance company. Unfortunalty your ds called his own insurance company and even though they will not pay to fix his car be ready to have his insurance go up. When my then 17 year old had a car accident my insurance agent said that they figure that every young person will have at least one accident. I hope that this minor one is your sons "one accident". Good luck.