Excellent question. And what if the other party, at fault or not, is not a driver? What if they are a pedestrian or a cyclist? What if they are alone, incapacitated and need medical help?
Although self-driving is a hard problem, automatically determining that the car may have had an accident and alerting humans in your control center is a much easier problem. I imagine the control center humans would be responsible for calling 911 if there was an injured human. They would probably be able to see out all the cameras in the car to help make that determination, or if the cameras are all malfunctioning you probably want to dispatch ambulances anyway.
OnStar Corporation is a subsidiary of General Motors that provides subscription-based communications, in-vehicle security, emergency services, hands-free calling, turn-by-turn navigation, and remote diagnostics systems throughout the United States, Canada, China, Mexico, Europe, Brazil, and Argentina
What do you do if you are HQ in charge of an expedition team going along a pre-determined route and the team suddenly and abnormally loses communication with HQ?
What do you do if a flight suddenly disappears over the ocean on air traffic control, and there happen to be some other planes and ships in the area?
What do you do if a hiker doesn't come home and they left a note saying which trail they were going on for the day?
I have a sneaky feeling that detecting whether a driverless car has hit a cyclist is not an easy problem. I can imagine scenarios where the contact took place towards the rear of the car (and therefore not at the primary focus of sensor attention), the cyclist goes careening off to the left or right and the car blithely goes on. I'm not saying such a scenario is impossible with a traditional car but it's a dam sight harder to ignore.
Do driverless cars have their kind of blind spots?
How about dealing with potholes? Do they also swerve around to protect suspension or just ram through?