Yep... that sound of my uke choking. I intended a blood choke and got windpipe instead. I slapped it on fairly quick because we were doing knife disarms.
Sunday morning Peter had us doing all sort of knife disarms but we spent a portion of the class working on a different situation. How to do a disarm when the knife is reversed. Usually we practice so that the knife is held outward so it can stab or slash. This time we held it reversed so that the length of the blade ran along the forearm. This is obviously really good for getting in close and slashing.
It leads to difficulties. Because of the position of the blade some of the usual hand/wrist grabs that we do to control the knife hand don't work. So Peter opened it up and asked us to see what we could come up with. There were a few different ways the students came up with.
One was to stop the knife by almost catching the hand. After that you could do whatever you liked. I didn't like that very much becuase it was too easy to miss the catch and end up with a sliced hand.
One way I first tried was to wait for the slash to complete and then quickly enter and make sure that I had one hand on the back of the elbow. That was so that he couldn't swing the knife back at me. At that point you can do whatever. I opted for the choke I described above. One hand controlling the knife hand wrist(back of the wrist, the other hand on the neck using the thumb to push the head. The whole body is brought backwards so they are relying on you for their balance. You can kneel and hyperextend the elbow or just choke em at this point. The problem with doing all of this is that you are forced to wait for a good opportunity to get in.
Next I tried something totally different. I matched the attack. If the attacker was right handed, they would be slashing from right to left from their perspective. I would enter to their open side and tenkan 90 degrees. Sort of like what Alan likes to do for yokomenunchi shihonage. I atemi as I enter with my right hand. Oddly enough the left hand is in a great position to block and grab the knife hand. You are inside the range of the attack. So at this point you can do whatever.
Peter seemed to like this idea the best. As uke you are keeping out of range of the knife and entering at the same time. It's also very easy to do that block without needing perfect timing.