The laws menstioned in the article already provide some examples: when the owner tampers with the vehicle, fails to have it serviced properly, or doesn't install critical software updates. There are some other examples, depending on your local laws. Here in the Netherlands, in accidents involving a car and a bike or pedestrian, the car owner is always held liable (not responsible, but liable) unless they can show intent or gross negligence by the other party, which almost never happens. Not looking while crossing the road or not having proper lights on a bicycle doesn't count, for example. Without getting into the rights and wrongs of such a rule, it does mean that not all of the liability for accidents involving SDCs can be shifted to the manufacturer, if it can be shown that such cars can not reasonably be expected to account for all possible misconduct by other road users.
But like the GP I expect that the point will quickly become moot: if the accident rates drop far enough, car insurance will take the form of regular 3rd part liability insurance (price of a few cups of coffee)