It's not that hard to believe humans on their phone are more accident prone than machines. What's hard to believe is Tesla would turn off self driving a second before a crash to pad their stats.
		
		
	 
I don't trust Tesla to not fudge the numbers, but I'd guess that people slam on the brakes of the car a second before the impact and that shuts off the autopilot, not that Tesla is being nefarious here.
Waymo's accident rates show significant improvement over human drivers.
		
 
		
	 
If you are on autopilot it will force end the session if it doesn't find a way out. If applying brakes it doesn't suddenly stop that.   It's rather clear when it happens that it wants the person to find a way out by steering if necessary. 
It has been at times spooky good at spotting issues more than a car in front.
Where it still struggles is in uneven lighting like shade from a bridge into direct sunlight. Lidar was built for those cases. That Tesla has walked away from lidar due to early costs will hurt.