It can get even worse.Since it was a single-car accident and your son was behind the wheel, he would normally be found at-fault and thus liable for the damages he caused. This means if the car owner can't file a collision claim for the car's damages, she may look to your son for the cost of repairs, or the actual cash value of the car if it were totaled in the accident. Your son should check to make sure that the car owner can make a collision claim for damages to her vehicle. Typically, collision coverage will extend beyond the car owner and to others that have permission to operate the insured vehicle. If your son hit anything else with the friend's car when he ran off the road, such as a guardrail, then the owner's property damage liability coverage should cover that, up to the limits of her policy. It may be a burden to pay these expenses, but since overcorrecting has been said to make up more than 4 percent of auto accident fatalities each year, he should be happy that he was able to walk away from this wreck.