John,The rifle would be pointed on a downward angle causing the muzzle flash to be lower than the user. Also, you would probably have to adjust the location of the muzzle flash for the angle where Mr. Bell filmed from.If it is not a muzzle flash, what do you suppose it is? That flash does not show any signs of a burnt frame in the film. A burnt frame at the same exact place on the frame where there are people with what seems to be a rifle would be too coincidental in my view.
It's nothing but an anomaly on the film. Better copies, like the copy owned by the Sixth Floor Museum(they have the original) show it to be nothing more that an anomaly for one frame. On top of this, it that were a "muzzle flash" it would be a cannon going off. No rifle would produce a muzzle flash that size and that color, which is solid white. This is the frame with the white spot from the copy of the Robert Hughes film owned by the Sixth Floor Museum:
Is the still frame you have posted from the Bell Film? The still frame posted "Bell Film" looks different than the still frame you have posted above.
No, as I indicate with the frame I posted, it is from the Sixth Floor Museum's copy of the Robert Hughes film, not the Mark Bell film.
