Yeah, watching the video, the vehicles behind had every opportunity to prevent the accident(s). They were all following too closely (in general) and didn't decelerate in proper response to the conditions. I've had vehicles literally pull out in front of me (like crossing the road I'm on perpendicularly) and I still braked to a correct extent to avoid t-boning the idiot who made a colossal mistake.

The person who hit the Tesla could absolutely without question have avoided hitting them. They barely even brake. There's really no excuse. It shouldn't have even come close!

Emergencies happen, sometimes the person in front of you may completely slam their brakes on. In this case, the Tesla was WELL into the lane before they braked, so the driver behind already had every opportunity to ensure proper distance -- the Tesla had long since become "a vehicle in your lane in front of you".

Further, so many of the drivers in this video have a serious lack of driving skill, as they simply maintain speed and try to swerve around, creating dangerous conditions for themselves and everyone around them.