In the movie there is a scene where the group grab the police commissioner at fund raiser and drag him into the bathroom to threaten him so that he doesn't follow through on a vow to take down their group. My confusion comes from the fact that Brad Pitt punches the commissioner and drags him into the bathroom while Ed Norton locks the door. Now considering the twist of this movie this is the one scene that I can't figure out how it's possible to both drag a guy and lock a door. So how did it happen?
I always took that to mean one of the Project Mayhem members locked the door. Edward Norton's character imagined/remembered that it was him instead of someone else doing it. Presumably this was guided by Tyler.
We see Edward Norton's character imagine himself doing things at other points in the movie. For example during the Tyler and Marla having sex montage, Edward Norton walks up to Tyler's bedroom door and peeks in. Tyler and Edward Norton have a short exchange, Edward walks off, then Marla asks Tyler, "Who are you talking to?" which indicates that Tyler was in control of the body at that point.