[fastpat]

Many or most states have a minimum damage that has to occur before the accident meets mandatory reporting. Your risk, though low, is that he'll try to make a claim against you to get his car fixed.

Personally, I'd keep his info just in case, and not worry about it. As far as the guy not having insurance, that doesn't mean he's off the hook if he did significant damage to your vehicle or any other property. Insurance is to protect him as much as it is to make you whole. If he broadsided a $50,000 car, and your insurance only paid $45,000, you'd be able to sue and get a judgement against him for the $5K.