- The villain's name is Castor. Castor is a type of Legume(A family closely related to beans.) that people often mistake for a type of bean. In the film, Castor successfully convinces everyone he's Archer by donning his face.
- Castor and Pollux are the twins from the constellation Gemini, the twins. On the opposite side of the star calendar is Sagittarius, the Archer.
- In Greek mythology, Castor and Pollux come from the city of Troy.
- The blood types for the two main characters (i.e. Sean Archer and Castor Troy)are mentioned in the movie, and at a subtle level they reflect their antagonistic nature. Archer's Blood type is O negative, while Troy's is AB positive, these two blood types are as different as you can get. O negative- the universal donor reflects Archer's role as a policeman dedicated to serving the community, while Troy's AB positive - the universal recipient suggests someone who takes from society without giving anything back.
- If Troy and Archer have differing blood types and this fact is a plot point in getting Archer's wife to realize Archer is Troy, how come Archer's body didn't reject Troy's face when it was put on him?
- How does his wife not notice his penis is different? Something brought up by many critics, including Roger Ebert.