There's a difference between the same thing happening on a Nascar Speedway and a dimly lit dirt track. Did Stewart have a radio in his helmet? Did he have a spotter at the top of the track? I genuinely don't know. I do think the track is much, much darker than a Nascar track. Also, they're on dirt and not asphalt. That's why the guy got bumped with the ass of the car. It look like Stewart swerved low and tried to avoid him. I'm guessing they were still going around 50 mph.
If this were Kyle Busch, I would be in the same boat with OB, showing my bias.