Not killed purposefully.
Temper your comment same way Stewart and Ward Jr should have tempered their actions.
NO one can prove what Stewart was thinking or what happened.
History can lead us to believe Stewart has this kind of disposition.
As I said from post 1....it looks like he gassed it and steered into Ward Jr.

I wonder if any communications were recorded during the race like in those NASCAR races?
If so....that would be the only opening for some sort of prosecution trying to establish Stewart's frame of mind.