- The Cast Showoff: Sally Yeh was a popular Hong Kong pop star — Jennie's ballads in the film are in her own voice. She was so popular at the time of the film's shooting that she could not totally fulfill her schedule due to conflicts with her concerts.
- Completely Different Title: The film's native title was Die Xue Shuang Xiong ("Bloodshed of Two Heroes").
- Deleted Scene: Scenes cut from the film:
- Li rescuing Jennie from some muggers in the same manner that Ah Jong does. It also includes a nice little reveal where we see that Jeff has seen the whole thing. The scene continues with Li taking Jennie back to her apartment, and Li seeing Jeff watching from outside.
- Li arriving at Ah Jong's apartment after the shoot-out just as the former is leaving.
- Ah Jong and Jennie driving from the airport and arriving at Sidney's safe house.
- Ah Jong and Jennie having breakfast at the house. Then Sidney arrives.
- The Hitman With No Eyes arrives by the creek and finds Ah Jong's bandages.
- Executive Meddling: Tsui Hark, the film's producer, attempted this multiple times on John Woo as an extension of their disagreements over A Better Tomorrow II. Tsui Hark originally wanted nothing to do with the film, saying "nobody wants to see a film about a killer", and forced Woo to change his intended jazz song opening to a pop song, claiming that Hong Kong people didn't understand jazz. He also attempted to have the film recut to focus on Danny Lee's character, but John Woo refused. Since he demanded this so late into post-production, Tsui Hark was not able to recut the film himself. When the film was greeted with high praise in its Taiwan premier, Tsui Hark was supposedly so livid that he trashed his own office.
- Inspiration for the Work: John Woo cited Le Samouraï as an influence on the story. Woo borrows plot elements for the film, including the set-up where Jef enters a nightclub and looks at the female singer. Woo also described the influence of a Japanese film, Narazumono, about a killer (Ken Takakura) who only kills delinquents. When a mob tricks him into killing an innocent person, he swears revenge but then meets a woman who has tuberculosis and wants to go home. The killer promises the woman that he will take her home after getting his revenge.
- Orphaned Reference: When Ah Jong and Li leave the church, you can see smoke in the background. This is the result of a deleted scene where Frank throws a smoke grenade into the church.
- Throw It In!: The film's subversion of Died in Your Arms Tonight during the ending was originally meant to be played straight, but John Woo was forced to improvise due to scheduling conflicts.
- Too Soon: The film did not do well in Hong Kong because audiences didn't like the allusions to the Tienanmen Square massacre.
- What Could Have Been: The original ending of the film involved Jennie waiting at an airport for Li to give her the money and for them to travel to the United States. Due to Sally Yeh's tight filming schedule, the scene was not filmed and replaced with Ah Jong playing the harmonica.
- Writing by the Seat of Your Pants: John Woo went into filming with only a short treatment for the film and wrote the details of the script while filming.
- Written-In Infirmity: During the assassination at the boat race, Ah Jong wraps a bandana around his left hand. At the time that this scene was filmed, Chow Yun-fat was simultaneously working on A Better Tomorrow III: Love and Death in Saigon. On the set of that film, he cut his finger on the front sight of an Uzi submachine gun during a stunt. Afterwards, he went straight to the set of this film to shoot the assassination scene, with his hand still injured and the bandana wrapped around it. John Woo decided to include this in the film.
Trivia / The Killer