I don't think he was going to show the whole 10 minutes waiting taking up his movie time. He does make available the outtakes showing the rest of the procedure. Yet people out there claim the whole thing was staged, when it was definitely real. Kooks like that do a disservice to those pointing out the real lies in the movie.
I can't believe I'm defending this POS movie, but that scene isn't enough to get me riled up.
Regardless, it was still designed to mislead. As Moore himself admitted in his little rant, the bank was a licensed firearm dealer. What he did was absolutely no different from going into a gun shop and buying a weapon. But of course if he had filmed that, it wouldn't have raised any eyebrows. He was simply trying to distract people into believing that the bank was engaging in reckless policies, by playing up the fact that he was in an unusual location. So in that sense, it was staged.