Don't be worried about the fact that you may have had a car crash with somebody who caused the crash, but wasn't the actual owner of the vehicle. That almost never is a real big problem, and actually sometimes it works out for the benefit of the injured person.
Growing up in Colorado my dad had me believing for years that if I loaned my car to somebody they wouldn't be insured on my car. That would be an uninsured vehicle on the road. Through High School that pretty much kept me from loaning my vehicles out to folks. Now doing this for a living I'm wondering how much other confusion parents have instilled on their kids on that issue.
Let me set the record straight. In Colorado if you loan your vehicle to somebody they are covered under your insurance. Which means, if that person causes an accident with your vehicle, then whoever they hurt will be compensated through your insurance under what's called Permissive User. As long as they were a permitted user your insurance will pay for the damage that person caused. Additionally, for the person who gets injured that way, not only can you look to the insurance for the vehicle that was permissively used by permission of the driver, by the owner, you can also look to the insurance wherever it may be in the world.
The person who borrows vehicle "A", but has himself vehicle "B" garaged at home somewhere, you could be looking at the insurance and we frequently do. We look at the insurance, and get the insurance from the car itself, but also from that second car, car "B", sitting in a garage somewhere. Don't be afraid in a situation where you get injured and you find out that the person who was driving the car wasn't the owner of the vehicle. More times than not that works out okay, and sometimes even better than otherwise.
