I viewed OP's zoomed and stabilized video here and spotted the figure; it seems to be wearing some type of helmet?

{ Figure with helmet? Two images; the second one has a red circle that I added to help point out where the figure is. This is the figure which moves from right to left.}

Maxed out the resolution, set speed to .25x and used the arrow keys to manually skip ahead. It took some doing of alternating with the arrow keys to dial it in so to speak. Set it to that speed so it'd be easier to find it. Someone can see this if they slow down the video and max out the available resolution, it's there for but a moment and moves off to the left.