I've watched a few videos of this. None of them provide any video of Stewart's car in the seconds leading up to the incident. At most you see a half a screen's worth of "lead up" (.5sec or less). Everyone was apparently "zoomed in" on Ward (the driver who was killed) as he was walking/charging down the track, arms all over, yelling at Stewart as he came around the track under caution.
1) There was a car in front of Stewart that also appeared to come pretty close to hitting Ward. That car did not "go low", either. Ward didn't back off as that first car came around, he took another stutter step or two toward Stewart's car. As he was first walking around his car, a couple of cars went by, some high and some low.
2) The lighting on the track was poor (typical of dirt tracks) and Ward was in an almost entirely black fire suit. HE could very well have been difficult to see. This was a dirt track, there is no telling if Stewart's vision was partly occluded by debris on his helmet's wind screen.
3) I've read some comments and reporting on this that say Stewart "gunned" the throttle, kicking the back out which made contact with Ward. In the videos there is a short blip of throttle heard in the second or two leading up to the contact, but it is not at all clear if it was Stewart's car that made the noise. People at the track may well have been able to pin point the source, aided by being able to see Stewart's car kick out as a result of the blip, but the video does not show the car kicking out (no lead up video as I said above) and it is not remotely possible to say the throttle blip was Stewart's by audio in the the video's I've seen.
4) Even if it was Stewart that blipped the throttle, this is only bad if he knew that Ward was charging down the track and was in proximity to the line he was driving.
All reports I've read so far indicate this is not being investigated as a criminal matter. That may change after they review videos being sent in from spectators and whatnot. But at least at the moment the police are not saying or implying there was any criminal wrong doing here.
All of your negative points are valid, though, Tony. In addition, Stewart caused a serious accident at this same track almost one year ago in which a couple of people suffered significant injuries. This is a knock against him, but it is also a reason to be a bit skeptical of some of the eye witness accounts coming out of this. There was no love loss for Stewart at this track from these racing fans and that may be coloring some of the commentary come out of the spectators who witnessed it.