Hold on a minute, Kat. I know it's brain-dead to be concerned about the car before your son, if that's all he really thinks about. But perhaps he jumped to the conclusion that if S17 was hurt then S14 would have led off the conversation with that. And since she apparently did not, then he must have automatically assumed only the car had been damaged. Not too bright and certainly insensitive, but I wouldn't make it out any worse than that.
In any event he does owe S17 a call to at least commiserate with him on his bruised emotions -- never fun to be in any sort of accident, even if no one was injured.