I know that's his philosophy. But as someone who's a rules-based learner, it makes it really hard to learn anything when I start focusing on a mistake and wondering how does this fit with the general rule, etc.
And beyond that I find it much harder to unlearn something wrong than to learn the right thing to begin with.
It might be a good philosophy and practical for classroom teaching, but he needs to use the advantages electronic media offers and do some editing. At least to remove anything that's really going to throw a student off and possibly even discourage them.
Leave the mistake in and then correct it.
I think leaving the mistake and correcting later is very confusing and possibly discouraging to students. What is your response to that?
In the same video, note your mistake and correct it.
I don't see why you would want to leave the mistakes in there. Someone might not grasp the correction!
I just remember getting incredibly frustrated after basically learning the wrong thing in the first video and then having it corrected in the second.
Maybe youtube isn't the best medium for his videos and he should instead find an option that allows and easily facilitates future edits.