Yeah, the button position thing went totally unremarked. I only realised thinking about it later to post. "Can he actually buy the button" covered it up. Presumably a player moved it without saying so and then the dealer moved it again. I don't know if someone else at that end got up (I don't think so, but...), or if they were just all out of position without noticing. The 8 seat was a reg who should have a clue, the others probably not. I thought about leaving that whole issue out of the post so it wouldn't distract from my actual question, but figured someone would notice if I did.
What I'm questioning is the sequence of hands (if we ignore the button placement issue):
9 BUT
10 BTB
10 BUT
1 BB
10 BUT
1 SB
2 BB
Because if the guy on my right buys the button, I should be SB the next hand, and if that's not correct he's usually told he has to wait for the button to pass.