Here is the still image from the video:

• A muzzle flash normally shows as a "ball" of luminous high pressure hot gas in front of the muzzle. In the image there is no "ball" of light in front of the muzzle. It is the snow on the ground being lit by the light. It is also too far from the muzzle to be that.

• There is also what initially appears to be muzzle glow directly at the muzzle. But that white streak near the front of the rifle cannot be that because muzzle glow is orange-red, not white and would not last long enough to make a streak on camera. It is the light itself. The muzzle flash would have also washed it out from this angle as it is supposed to be a lot less bright in comparison.

Nah, Wehrmacht != Waffen SS