Additionally, how can you blame the driver? Did you watch the video? It's not as if the car slowly stopped. It slammed on the brakes. There wasn't time for the driver to correct for this before the car behind -- which Autopilot had just moved in front of -- slammed into them.
Tesla's Autopilot and Full Self Driving get a lot of focus and criticism for two big reasons; 1) their product names clearly and deliberately paints a picture that the features do not live up to and disclaimers do not fix that. 2) they are unsafe on public roads as they operate today. They are a menace to public safety.