The MMA guy (or wrestler) looked to be considerably bigger than the Kung fu opponent. Not that it matters that much, I'd expect any decent MMA practitioner to easily maul a Kung Fu guy. A good striker will always lose to a good wrestler or BJJ guy unless his take down defense is top notch.
As you can see by the comments for that vid a lot of people in Kung Fu (and probably other traditional martial arts) are labouring under the delusion that there are a bunch of guys out there that could easily defeat mixed martial artists. The reasons offered for why the don't are because they 1) choose not to because they won't lower themselves to fighting or 2) that they can't get into MMA because they are too poor or so removed from professional MMA.
Neither argument stands up well. There is no real stigma attached to MMA. It has rules, referees, judges and is sanctioned. It isn't a streetfight so the idea that these mystical kung fu masters are somehow "above it all" doesn't hold water.
Secondly, plenty of piss poor countries still manage to get athletes to the olympics and other competitions, especially China. China in fact loves to demonstrate athletic superiority so if these guys really could dominate then they damn well would get them over here and do it. They don't because....they can't.