I can't see the helper pulling the sleeve through his leg. What I do see though, is very agile helper work. The helper changes foot placement, and has the right foot forward; he has already seen the dog will come in a bit left of center of mass. His weight is on his right leg, which allows his left to come up easily, and he safely absorbs the dog's impact. It's quite hard to absorb a dog that comes in left of center of mass, with a left sleeve on, when the dog comes in low"ish" and very fast...and make it look good. He got his left leg out of the dog's way in a hurry.
The first helper, in contrast, is a HARD helper. He does not get out of the way.