I always thought any rear end accident is the fault of the vehicle driving into the rear of the car due to not leaving enough distance to stop safely.
It is...........
Not always.
I once had a "Hot Hatch" run into the back of me. I was about to turn into a narrow works entrance when a lorry appeared in the entrance and I had to anchor up.
Car hit me from behind. I wasn't insured. (company car cock up)
I had to go to court to get the other guy to pay and the Magistrate decided 50/50.