Revealing mistake: In the scene where Zuckerman is thrown to the floor in the gym and handcuffed, you can hear the handcuff ratchet click as it's placed and closed on her wrist. As the other agent moves away, you can see that the handcuff is open and not actually closed around her wrist. (00:31:00 - 00:31:50)
Revealing mistake: Mary Gross' character, Janis Zuckerman, picks up a sailor at a bar. She says she wants to dance with him, tries to drag him onto the dance bar, instead she's drunk and falls onto a table. While she is falling onto the table you can see the double they used has very long hair, versus the Gross' boy-cut.