I saw the video, and if I were on a jury, it would be tough for me to convict Stewart of anything as a first instinct. I've watched some races, but not dirt track races, and never driven. I've seen drivers get out of the car and yell at somebody before, but I've never, ever seen anybody go that far down into the racing line to do it. So, instinctively, as a casual fan of racing, I think I'd believe Ward to be at fault both criminally and civilly, absent Stewart saying something incriminating about intent.
Because I'm only a casual fan, I could imagine hearing expert testimony that would convince me otherwise. It would have to be the case that what Ward did was much more the norm at dirt tracks and that experts felt Stewart clearly veered towards him, or something like that.
Having said that, there's absolutely no way Stewart should have been racing today, and if he weren't his own owner, I can't imagine it would have even seemed like a possibility.