It will be interesting when the 1st similar case happens in the UK what the police reaction is
I find it interesting that in none of these incidents is there much mention of the driver being charged with anything.
I don't know details of US traffic laws, but I'm 99% certain that if such incident happened where I live and the driver gave that sort of account the next words out of the police officers mouth would involve the phrase "You will be reported to the Procurator Fiscal for consideration of prosecution for offences under the Road Traffic Act".
The interesting thing is whether the charge would be "Driving without due care and attention" - a traffic offence carrying fine and possible license suspension or the more serious "Dangerous Driving" which is a criminal matter quite a few of the aspects mentioned would be likely to jump it up to the more serious charge.
Quite apart from the issues round Autopilot the police attitude here is that there is no genuine reason to run into the back of another vehicle, you were either driving too close, too fast, not paying attention, not driving to the road conditions or had defective brakes/tyres - and its almost automatic for people to be charged, unless they have a really exceptional excuse.