Don’t know if anyone saw this - didn’t see it posted - when Gallman did his two-yard leap to the end zone, about midway he was losing altitude, so he used his free hand to push down off the top of Perry’s helmet. It looked significant enough to push Perry down a bit. From the takeoff it didn’t really look like he had enough spring to go as far as he ended up going. So there’s the rest of the story.
You might conclude that Gallman has a lot of situational awareness for that move. He keeps looking more and more like an NFL back.