There is probably no doubt that the vehicle that was covered by the insurance was invovled in the accident. However, sometimes insurance policies have "exclusions" that apply to certain drivers or its possible that the car was stolen. In these situations, insurance coverage may not apply. That may be why the insurance company wants to determine who was driving. Follow up with the insurance company to get clarification. If there is homeowners insurance on your property, its possible you can make a claim through that insurance in the meantime.