No triangle as long as you keep your elbow on the inside. Werdum actually points out that his elbow is tight and can't be flared out for the triangle.
This pass is actually from Renzo's DVD's that he released 10 years ago with Craig Kukuk. First time I tried it, i kept on getting triangled cuz I kept on leaving my elbow on the outside.
One more thing to be careful is that when your arm is reaching back to open the guard, you have limited base, so if your weight is a bit off, you are leaving yourself open for the Mike Fowler style direct closed guard sweeps from the bottom.