Seriously, the last place anyone needs to be running around is an active racetrack, even under caution. Keep what's left of your car between your ass and the rest of the field and wait for the safety truck.
As for Stewart's actions, if he pimped the throttle passing Ward, with that exposed tire spinning, he may have well drove by and swung a running chainsaw at him.
Sometimes stupid doubles up, and when it does somebody always pays.
I still remember that horrible year of the Indy 500 when a guy was stuck and killed by an ambulance going the wrong direction on the racetrack.