I've always thought that the best way to REALLY learn something is to try to teach it to someone else.
Of course, that means that you cannot know it inside and out until AFTER you've successfully taught it. In reality, you'll have to successfully teach it to multiple (many) people under differing circumstances to really become an expert at it.
There aren't many folks out there who can master something, and also succeed at teaching others to master it.
What you find when you teach is that you're still learning it. And learning almost always has some "pain" associated with it. When you look at it that way you really can't expect teaching to be painless.
Sunka, I think you're seeing that. And I think that learning in front of others also leaves you (at least feeling) more exposed.
Don't worry about it!
Looking through your video there are a few things I'd "tweak" or reword; but that's me, and my style. As a used-to-be artist, I'd also be the first to tell you that I see plenty of flaws in my own work as well.
I often adjusted the way I worded or described certain maneuvers in order to help my pupils "see" what I needed to convey. I guarantee I occasionally "strayed" from textbook teaching to accomplish my goals. Teaching is tough! It's tough in "normal" teaching scenarios... It's REALLY tough when you cannot see your pupils, or his/her facial and/or body language, etc... Add to that the cultural and locational differences, and even some geographic variance in words/terms, etc...
While that's tough, I think it's even more difficult to produce a stand-alone training film. In the TA, we can repeat and reword and change tactics mid-way through to get our lesson across. Not so with a video...