glad you are ok, and sorry to hear....having been through this same thing I would highly suggest calling his insurance asap- I think most all have call centers running 24/7. I would suggest taking a severe and strong push on everything you can-record and document EVERYTHING. Get a copy of the police report asap. This policyholder sounds like he is the POS that would lie to his insurance as soon as he gets home.

In my last claim, I was "20% at fault" for being in traffic when I had my car totalled by a non-licensed, drunk underage girl running a red light. Yay tort reform and yay insurance companies. The policyholders' insurance held the line that if I had moved out of the way I would not have been broadsided.
You do have some minor recourse on an undervalued total, it takes a ton of time and effort. Lost value is also a tax deduction-which usually equates to about a $.0001/$ net.
And the ins company will give you a hassle about needing a same/same rental,
-in another incident- renting another truck ended up costing the ins company of the lady that rear-ended my truck about $8500 because it took so long and I also required one for work. They tried to weasel out of that one in every possible way-and a few that were just downright evil.

best of luck.