That triangle in that video is kind of a joke. If you can catch a guy sleeping he's dead. But once you go to your knees any half way decent grappler is reversing it easily. One quick bridge and either the guy on top is rolled to the bottom or he is launched out the gym.
I'm not saying that the triangle is a joke. It's great.
What I'm saying is once the guy goes to his knees in the video, right before he traps the arm, he is getting reversed. Any sub-par wrestler would reverse him on instinct of the pressure change.
Watch that video again and see the flaw of the transition. i wouldn't advise using it from there.
Not a very efficient move from side control.