Factual error: In the scene where Tommy Lee Jones's character shoots down the helicopter. The helicopter has a Canadian aircraft serial number - C-GLCD. Since it's being used by the New York Police Department in New York's Central Park we should expect it to display an American registered serial. (00:53:30 - 00:54:30)
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: 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.
Revealing mistake: When Eddy's mother is lying dead on the bed, she is breathing.
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.
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: 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)
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)
Continuity mistake: When everyone is having dinner and one woman is on the end of the table then it shows her at a different end of the table.
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.
Factual error: Ted Bundy is trying to pick up a potential victim in front of a record store, where a poster of Stevie Nicks' album, Rock a Little, is displayed. This scene took place in the mid-1970's, but Nicks' album was released in 1985.
Revealing mistake: When the bully's held up by Sam wires can be faintly seen.
Factual error: The movie as the opening captions say, is set in Melbourne, Australia, 1978. However when Sam at the beginning of the movie drinks the milk and moves to the other room where the TV is, he passes by a poster (a communist party poster, the Italian communist party, strangely enough) that was designed only in 1981. (00:09:25)