I think he moved ukes glute at that time and you know how the glutes gain speed without any reason right?
Same thing happened to me on MP.
When you move the glute, the groin that you call the small cuboid moves away from the glute a bit and then connect again in a different place so yeah, what you did was basically moving the glute. But don't get this as I'm trying to insult you or make your replay look sloppy, believe me, that thing is a masterpiece. I am just explaining the glute glitch which happens when you move the glute. Using that glitch for your skeet is incredibly clever.