> I was always taught that it was my responsibility to ensure that I have enough following distance, and am paying close enough attention, to stop if the car in front of you abruptly stops.
Brake testing (suddenly braking hard for no reason, what the Tesla did here) has always been a cause for the leading car to be the guilty party when they get rear ended.
In times prior to dashcams, it was difficult to prove the car ahead did brake to cause the accident, so the rule of thumb was the rear car is probably guilty. But if there was a way to show the lead car did brake, they're guilty.
Nowadays with dashcams, it's a lot easier to prove, so brake testers don't get away with it as much.
