[econonut]

The Tesla looks like it slowed down 200+ feet over 4 seconds. That's far from slamming on the brakes. It's also, however, very far from expected behavior which could explain why the drivers behind didn't slow down enough in time. They weren't expecting the Tesla to come to a complete stop. I'd guess if the other car was a Tesla it probably would have stopped in time to prevent the collision because it's basing its decisions on the environment not based on prior experience driving in that particular spot.

I'd also argue that the Tesla pulling over into the left lane (merge 1 lane left vs 3 lanes to the right) is the right behavior in a situation that warrants stopping. Try to get to the side of the road so other cars can pass.

[ruined]

that is, in fact, slamming on the brakes. your estimate of 200+ft over 4 seconds, assuming perhaps a low highway speed of 60mph, is faster than many cars are capable of stopping, even assuming zero reaction time.