Audio problem: When the helicopter lands and the teenagers cheer you can hear dialogue from later in the film in the background. Several times you hear "Sean, catch the rope." which they yell later in the movie.
Audio problem: The scene in Dudley Moore's apartment was longer than the song, "Stayin' Alive" that is playing on his stereo so the song is substantially longer by looping and replaying portions of the song. (00:30:20 - 00:36:00)
Audio problem: While Lynda is filing her nails just as Michael enters the scene wearing a sheet and glasses, the sound of her filing continues despite her pausing.
Audio problem: During the underground car park scene Glasses is heard yelling and cursing at The Driver to stop several times, yet whenever the camera is on him while speaking, his lips don't move.
Audio problem: During the dinner scene when Poirot finds an eel in his plate, the quartet plays a song in perfect classical music, but they are using instruments typical of the local folklore. A rebec does not sound like a violin. (01:42:55)
Audio problem: When David is in the steam bath talking on the phone, during the angle shot from behind, his voice is completely different as well as the background noise, much cleaner. It was very obviously dubbed. (00:39:40)