I just watched the video. The grip is exactly what I am talking about the difference is the direction you move your opponents arm. In the video you wouldn't be able to move to the back because he can block you with his right arm. The way I do it is to pop the right arm across his body and move to the same grip. Does that make sense? I have 3 different setups I work to get the arm across but that is the key, the arm has to be across the body so you can get around them.
The second variation he did where he underhooked the arm and grabbed cross collar is one of my all time favorite control moves from guard. I have never seen the triangle from there before and will drill that this coming week.
When you say gable choke are you talking about a baseball choke? BJJ has some crappy naming conventions so it is hard to have a discussion when you are saying the same thing but thinking different moves.
Here is a link for a no-gi version http://www.youtube.com/watch?v=4KlXBd9VAcM
I use a gable grip anytime I do this choke not the way he is grabbing.
What we think, or what we know, or what we believe, is in the end, of little consequence. The only thing of consequence is what we do. -John Ruskin