You guys are thinking this out too much… we have people pay out of pocket all the time down here and we rarely have problems with people paying. You don’t need the police involved… 90% of the time they won’t even come out of no one is hurt or there is no property damage, so there useless anyways.
Let him call his insurance company… DO NOT call your insurance company, it just makes more of a headache for you. There not paying, so they don’t need to know, simple as that. If the douche or his insurance company jerks you around, then its time to call your insurance company. Until then… screw em.
Take a picture of the damage, ill let you know if it needs to be replaced. If it does need replaced, you better take it to a good shop, a quarter panel is the worst panel you can damage on a car. It needs to be cut off and welded back on, you need to blend into the roof line, rear body panel, rocker panel, etc… and it can take anywhere from 2 to 4 weeks to fix, depending on how bad it is. Plus with your color, you will need to blend the paint into the liftgate and the rear door, which all need taken apart.
BTW - do you know who his insurance company is?