I am sorry to hear that the owner faced this problem. What is the owner's expectation in term of compensation?

Very unlucky and I think not much you can ask for compensation. It just like your car running on the road and someone suddenly hit you from behind.

What you can ask for compensation is what insurance can cover for you, repairing, parts replacement. Including some money to cover while you don't have your transport during the car sent for repair. This is covered by insurance as well.

Hope everything going well.