For clarity, and because I'm not trying to get all up in an internet argument, I called the first half of that video Weaponized Fuddlore, because it was set up to make it seem like "look how easy and fast these disarms are" and then demonstrated them slow, against an unresisting and non aggressing assailant. He's like 35% of the way to a DUST video in the first half of that.
Not saying disarms can't work, just that they don't usually like that. I might also add that like if you go into a knife fight, you're probably getting cut, even if you win: If you try to disarm a aggressor with a pistol, you are probably getting shot, even if you win.