When Mugatu is explaining to Derek why he wants him to campaign for him, Todd brings him a large coffee. Mugatu spits it out, with no foam mustache, and for a second a foam mustache appears. After Derek's surprised look, it disappears again.
When Derek finishes talking to Matilda on the Walkie Talkie in Maury's office he turned "left" to go back to helping Hansel look for the computer files. A large premise of the movie is that Zoolander is unable to turn "left".