Here's another video to explain:
What's that neck pinch the referee does at 2:44? It dropped the dude with a twitch.
And yeah, not a good referee.
Looks like a rabbit punch. Rabbit punches can be lethal. They're illegal in NJ's MMA law.
I'm not seeing a wind up for a punch. It looks like he just grabbed the back of the neck.
One thing is for sure, the guy who shows up with the long staff at 3:03 is there to keep the peace.
Looks like he pinches the carotid artery with his left hand and delivers a short knuckle strike to the back of the neck with his right (striking "Gall bladder 20" in pressure point topology). Attacking opposite quadrants of the head is like a double-bubble in the pressure point world. In this case it's enough to drop his man, albeit without knocking him out.
There's not much to be added to what Vieux Normand said up there ^^, but I trained this stuff for a while at a karate club about 18 months ago and found it to be a mixed bag. The points are there and when struck in a certain way can produce certain results, but a lot of the pressure point crowd veer off into the "meridian/chi flow" Dillman mythos about which it's easy to be sceptical. FTR I've been (briefly) KO'd twice off it, both times from neck strikes.
I gotta see where the book is....(pressure point fighting it is called i think).
And yes the referee was a fucking dick (albeit a bad ass dick), the head stomp in the end was so not necessary .