Yes, there is much to learn from this video. Some questions I had when I first saw this:
Why is he demonstrating grip with a loaded gun?
Why was his trigger finger on the trigger when not pointed down range?
Why didn't he admit his mistake?
We all make mistakes. I can respect a man who can admit when he's made a mistake. I have little respect for a man who tries to brush an extremely dangerous mistake under the proverbial rug.
I would not have stayed in that class.
I was in a shotgun class when an instructor had a negligent discharge. The difference between that and this is dramatic. In the shotgun class, the instructor was demonstrating a port load. At no time was the muzzle pointed anywhere but down range. His finger wasn't on the trigger until he was finished with the load and pointed properly at the target. It's at that point when your finger should be on the trigger. When the gun fired, he didn't try to brush it off as a gun malfunction or the ubiquitous, "I meant to do that." He manned up and admitted his mistake, profusely.
That was easy to forgive. The OP's video, not so much.
Freedom isn't free.