I'll forgive a human driver for not noticing a pedestrian and reacting in a quarter of a second. But all the marketing videos have trained us to hold an autonomous car to a higher standard. Certainly a lack of lighting isn't an excuse. The car should have known she was there, identified her as a potential hazard, and been prepared to take appropriate action should her course change. Speeding, along with the fact that the car made no attempt to stop before the collision, is a "back to the drawing board" level of failure.