So this just happened.
Caught him as he was getting out of the vehicle. OLD guy, maybe 85+. At first he tried disputing the fact that he made contact. Really?!
Luckily I got his ins. We both have USAA. They're taking care of it.
AMAZINGLY after I very carefully backed out, the only damage was a scuff on the mirror, and front quarter panel has paint damage. I thought it was going to be WAY worse.