car insurance borrowed car

A person who is carrying Bs person car, and is beaten by person C?
A person who has no car, so no car insurance borrow car B.. Person B has a safe in his car. Person C (who is at fault), also had no insurance. CP on stage (and 2 other claims adjusters) said the Person B insurance pays and goes after the person C $ $. Contacts Person B co-insurance and told, No, not paying, person A has to pay. What is the correct answer, and please give reference. Accident occurred in CA, if that makes a diff.
Insurance following vehicles, not drivers. It's sure B is active here. But if "the person C" at fault uninsured is not likely that you will get nothing. "C" is responsible its loss, and probably could get a trial against him, but how to charge less "C", who happened to have assets could connect. If "B" has no policy in the collision or uninsured motorist coverage, the insurance of B could actually say they would not pay. If there is coverage, which have to pay, minus any deductible on your policy. Unless one offers something that is basically off the hook here. In any case, find its loss and submit a request for payment letter to C.
Borrowed a car. Treated it like it was my own, by thrashing the hell out of it.