I do think there's a point where introducing different failure modes is harmful. Say they end up causing more pedestrian crashes and more head-on & angle crashes (such as the one in this article), but less loss-of-control and fixed-object crashes. That would make it safer for occupants but less safe for non-occupants of the self-driving vehicle. Since the occupant is the ones engaging self-driving mode they should be the one carrying the risk, so IMO even if it reduces number of deaths overall it should not be allowed