Plot hole: Much like the 1978 movie adaptation, in this version there is an absurdly short time elapsing between Linnet leaving the bridge table and the incident and murder; it's barely two minutes when she'd have to go to her cabin, do everything a proper lady of the time would do to prepare to go to bed, and fall sound asleep. That's because the witness character (Cornelia Robson here) in the novel is supposed to be droning about her boring life for a long time, but there are no gaps in her speech to imply that a long time passed - at most there's the waiter bringing a drink at the very beginning who sorta comes out of the blue.
Factual error: The night of the murder, before Jackie has her nervous outburst Ferguson is reading a magazine. It's Life magazine from January 1937 with FDR on the cover. The episode is set in January 1936 (as you can see from the date on Pennington's ticket).
Factual error: When Jacqueline surprises the Doyles revealing her presence on the boat, she was initially covering her face with the December 1938 issue of Vogue. The story is set in January 1936.
Appointment with Death - S11-E4
Continuity mistake: When Nanny Taylor is discovered in the bath and Poirot is leaning over her, her plait is first across her chest and then it is suddenly along her arm. This is most evident in the flash-back scene at the end.
Answer: He definitely says "Belgian", but the subtitles get it wrong and show him saying "American."
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