[Callers] Need help with "Mr Know It All"

Okay, I need some other perspectives on this. Last year we had a new couple move to our area, and start attending our local contra dance. They had danced "somewhere else" for several years, and the gentleman had obviously been involved in some of the dance organizing duties in their last location (web site upkeep, etc). First impressions were positive - he came to the dances for a few months and offered some worthwhile feedback, while also actually offering to take some action. He suggested we offer a waltz "lesson" for a few minutes before we have the first waltz, and he offered to "teach" the waltz, anytime and every time. So far, we have taken him up on this and it does seem to have encouraged more people to get up and waltz, which was the point. The emerging problem (I see..) is that he now wants to insert himself in the "contra dance lesson" before the dance, which we ask the caller of the evening to conduct. Several times over the last year, after I have done "the teach," (where I don't focus on new dancers learning moves, I focus on making them comfortable and getting them moving to music) Mr. Know It All has told me that several people "just weren't getting it" and he has offered to take them into a separate room to give them "more training" so that they "don't muck it up for everyone else." (Yes, these were his exact words). I have consistently declined his offers, as tactfully as I could. At our last dance, though, he had obviously made contact with the caller before hand, as he was taking the microphone during the teach and offering his "two cents worth" on contra dance set management, formations, etc. I don't think anyone died in the train wreck, but I see trouble ahead. (Didn't John Fogerty sing a song about this.??) My concern is that we have "given someone an inch, and now he wants to take a mile." This guy, due to his occupation, is used to coming into an organization and being the new sheriff in town, and I get the distinct feeling that he sees our dance group as one that he needs to "shape up." I am personally quite troubled by what I am seeing, but unsure of the best course of action. (In my view, he is a "bull in a China Shop" and he has broken quite a bit of china already...) I have seen other dance communities where a "dancer" does the beginner teach for every one of the dances, and when people in the community find that they need to make a change, they don't feel that they can, politically. (How do you "fire" a volunteer??) Have any of you had a similar experience? Any suggestions? Thanks!