Skuzzy, your reasoning is sound, except...
those are not stars; it's dust on the neg.
Even the most miniscule muzzle flash would drown out any stars in the background, especially if the muzzles are close to the camera, especially with a moving subject.
Also, If it was high-speed film, I would expect the prop to be not so blurred.
But it makes the point, doesn't it. Cool picture.