Character mistake: Carl, carrying his gun, goes up the outside staircase before entering Frank's apartment. When he encounters the frightened cleaning woman, he flashes his F.B.I. badge at her to identify himself. However, he only shows her the back of the black I.D. wallet, which has no markings on it.
Suggested correction: This was undoubtedly an intentional choice by the filmmakers. Given that most of Carl's work takes place in an office, it's entirely plausible that he would feel nervous when stepping into the field to apprehend a suspect. The scene emphasizes his anxiety through several deliberate actions: he fumbles for his gun, incorrectly displays his badge, and even holds it upside down if you look closely. These details subtly underline Carl's unease in high-pressure situations.
Character mistake: Although great care was taken to duplicate Bob Crane's distinctive hairstyle for Greg Kinnear, Bob Crane's hair was actually parted on the left. The makeup department for this film parted Greg Kinnear's hair on the right, producing a mirror-image of Bob Crane's hairstyle.