Continuity mistake: When Peach collapses on top of Mario after the weird TV invasion, Mario's arm is on top of hers, but in the closer shot that follows his arm is distant and in fact it is behind hers the moment he turns a little.
Continuity mistake: After Eugene takes the stage to face Jack Butler, everyone (including Eugene) turns when Scratch walks into the room. When Scratch sits down and Eugene turns back to face Jack Butler, Eugene's hat is gone.
Other mistake: Maureen cuts her wrists with a razor blade. Days later, no bandages or scars.
Plot hole: Chelsea says that when her deceased father gave her one of his paintings (now missing), he wrote an inscription to her on the back. She says she cannot prove that he actually did this other than he noted it in his journal and she does not know where the journal is. However, when Chelsea's father presented the painting to her on her 8th birthday, there were at least 100 adults present at her party who witnessed him giving her the painting, writing the inscription, and signing his name on the back of the canvas which was displayed to the guests. Any number of these people could be contacted and corroborate her claim.
Continuity mistake: Poirot met Ariadne Oliver who invites him to the "murder hunt." Poirot and Hastings then get on a boat to head there. As they sit on the boat, there are a few extras, led by an easily identifiable lady in a yellow sweater, that move up the stairs of the pier and reach the top. The boat slowly takes off, and about 10 seconds later we see the pier again, with again those same people from before just reaching the top of the stairs. (00:02:25)
Factual error: The brothers had a two-way mirror installed in the fitting room. Todd makes faces at his brother through the glass. If the mirror had really been two-way, the woman would have seen the reflection of Todd making the faces and would have known something was up. (00:19:28)
Continuity mistake: To reach Poirot, Hastings walks through the Acapulco airport with two ladies (one with a white jacket, light blue skirt, updo, carries a large brown suitcase, and another one with short hair, glasses, white trousers) that are both in front of him AND behind him, depending on the camera angle. (00:01:30)
Other mistake: The end credits are plagued by the biggest compilation of spelling mistakes you'll ever see. The French cast in particular has 2 out of 2 actors with their names wrong (PallarOy instead of PallarDy, a female, Danièle, turned into a male Daniel) and so many errors in the technical cast to make some of them impossible to identify.
Continuity mistake: Marjorie sprays the rapist in the left eye, mostly, with insect spray, but later it is his right eye that is affected the most.
Visible crew/equipment: When Crispin Glover goes into a telephone booth to make a call, the cameraman and his camera are reflected in the glass.
Visible crew/equipment: When Skip has just finished snorting cocaine and is talking to Stella, the boom microphone is visible on the top left of the screen.
Continuity mistake: Martin McNamara calls his brother at the beginning of the movie and tells him he'll be ready in two minutes. When the camera cuts to a new shot, his grip on the phone changed entirely.
Continuity mistake: Allison's high heels go from off to on several times when she's walking with Keith.
Other mistake: The subtitles of the international version translate a few things completely wrong, including, when the body of the warden is found, "There were three men!" instead of "It happened at half past three." (00:04:25)
Visible crew/equipment: A film crew member wearing a white baseball cap and dark blue T-shirt is seen in the shot of Cliff, Lance, and Danja escaping from the smelter facility.
Visible crew/equipment: In the opening sequence, Sammo Kam-Bo Hung is scavenging the dead soldiers (with one hilarious twist) - however, when he is holding the ring, in his sunglasses you can see several very much alive crewmembers standing. (00:02:45)
Revealing mistake: When Samantha kills Mrs. Parker by crushing her head with the basketball, the dummy replacing the woman is visible.
Continuity mistake: After the car accident, a man in a black hat and coat runs up to the left-side rear window of Patton's car, taps on the glass, then peers into the car. The camera angle changes to show the Jeep arriving and we see the same man in black arrive again to repeat all the same moves exactly. (01:13:30)
Continuity mistake: David Chiang chases the man in a purple dress at the 1985 Hong Kong Marathon. He fires a warning gunshot; if you look at the guy in the back of the pick-up that the criminal is about to hijack, he lets go off the bar twice in two different shots. (00:02:35)