October 2 was a quiet night on the streets of San Francisco. It was moderately cloudy, and Fleet Week activities had just begun at Sunset Library. But in the Tenderloin neighborhood, at 9:29 p.m., a pedestrian stepped out into the street, crossing Fifth and Market, and was struck by a green Nissan Sentra sedan. What happened next would ripple all the way through one of the largest corporations on earth—GM. Because after the woman was struck the first time, “Panini”—one of the self-driving robo-t...