don't complain to HR and don't let this hurt colleague relations

if you do, HR is not a babysitter they will not intervene; in HR eyes you might appear to be somewhat immature.  from another angle to look at it, he didn't invite such an incident, he deserves a repair. there is no clear cut what are "prior" what are "now".  whatever number he gave, he can say it's a bodyshop's estimate.  just hand it to insurance, you guys can continue to be nice colleages (it's important to remember - don't make enamies in workplace, and in neighborhood, even though sometimes you may need to "Ren3").