Ok so we are on basically the same page regarding what that choke is. Now I did ask if you considered that the choke was taught in an overly aggressive manner. Which of course it can be. But the choke itself is a very common way of getting a submission. There is a nastier application of the wind pipe idea called the 10 finger choke. And that is legal as well. I will hunt down the C class rules (or what you may suggest as amateur) regarding choking and neck cranking.