The photos. Thecwhole thing was photographed extensively.
Go to tmz.com for the smoking photos.
That explains why the window was down, but not why he was following so close and couldn’t stop. I guess we’ll know for sure once the phone records come back. As I said before, if the paparazzi made her stop short they will be on the hook. But he furthered the chain reaction so him hitting the Lexus is still his fault.
As far as establishing blame, it doesn’t make a bit of difference whether (s)he was holding a cigarette or a cell phone.
He rear ended another car because he was inattentive or following too close as the other car slowed due to the fact that they were approaching an intersection.
The standard excuse in such a situation is that the car in front braked suddenly. That excuse almost never works. Nor does claiming that paparazzi are chasing you.
In any event, the cops will have readouts from both cars’ computers, they have the photos, and there are witnesses.