Here is another post from the news that might help some people understand...
This was posted by one of the people who works on the car in front of Tony Stewart in the video. Definitely worth reading in my opinion.
From Mark Tychoniewicz
"i have driven these cars,the right side board on the top wing will block out an entire car let alone a person standing there,i now work on the 45 car in the video and the driver said he just saw at the last second and just missed him,Tony had even less time to react to the situation.people in the stands or watching this video have no idea how fast these thing happen and how limited our view is inside the car.it was a very bad turn of events that happened but we all know the dangers involved in the sport we love."
Also for those that don't know, sprint cars on dirt are driven by the throttle rather than the steering wheel in some cases hence the reason you hear Tony's car throttling up. Just for the record I am not a Stewart fan but he was not at fault.