I give my props to this guy.
Not to take anything away from this guy but his opponent I think was pretty green at best. It would be hard to grapple this guy because arm/leg/heel bar would be out of the question. The only thing I can think of at this time to win against him would be to choke him out or exhaust him by using your full weight on him. There are probably other ways but the only two that come to my mind at this time. If his opponent had good upper body strength then he would be tossed around alot. I think because he does not have any limbs then his weight keeps him down in the lower weight classes, as the guy he grappled against couldn't have weighed more then a twig.
Again I give this guy his dues as when I grapple I use my arm and legs a lot ... and am just getting into realizing how much more I can use my legs like hands to pull, push, lift, etc. This guy is limited to what he can do and he still uses that to his advantage.