Could it possibly be that there won't be legal issues?
We all pay (or should pay) for car insurance, the cost of which depends largely on where we live and how likely we are to have an accident. If we do have an accident we let the insurance companies sort it out and only care because our premium may go up as a result if the incident is found to be partly/wholly our fault. Drivers will lie about the details of the incident to try to push blame away from themselves to avoid loss of NCD and prosecution.
Driverless cars will record all events up to the accident, so no lies from them and the blame can be fairly attributed. There will be no loss of NCD and no prosecution because there is no driver. If (say) Ford cars are found to be at fault in more accidents than average, the premium for those cars will go up, but not because of one particular accident.