I wonder why everyone thinks that UTG is the one pulling the angle-shot. I would guess that, if BB had AA instead of 77, or if UTG didn't have KK, BB wouldn't be the one complaining about the size of the bet.

The common sense thing to do (though not exactly in line with Robert's Rules) is make BB's bet $2000. Reason? He asked for a count and was told $2000. IMO, BB called a $2000 bet. To rule otherwise is to reward BB, who seems to be more upset that he's an 80/20 dog.