Factual error: At the end of the episode, Hastings is reading a sports newspaper. The episode is set in 1935, and a weekend, but what he is reading there announces the jockey Billy Parvin substituting Fawcus riding Galdennis, and Golden Miller and the ticket for the sweeps, making the newspaper a March of 1933 one. (00:50:55)
Continuity mistake: Hastings buys a large scotch for Rupert Carrington. You can see in the wide shot Hugh Fraser with his right hand raised to give the coins to the bartender. But in the next shot, Hastings' hand is not in frame yet, and he even ends up paying with the left hand instead. (00:30:00)
Factual error: Florence Carrington is killed on the train while she is leaving London for the weekend. When Poirot and Hastings examine the newspapers she could have been looking the day she was killed, the headline of "The evening news" in Poirot's hand announces the world record set by Malcolm Campbell at Bonneville Salt Flats in Utah, which happened on 3 September 1935, a Tuesday. (00:27:40)
Continuity mistake: At the hotel, the Count is checking in. Behind him by the revolving doors you can see three people having a conversation, with one being a woman wearing a distinct floral dress and brown stole. He steps away from the concierge and the same woman is having a chat in a different part of the hotel, right part of the frame. (00:03:30)
Continuity mistake: When Miss Lemon announces Mr. Halliday, Poirot has two open letters on his desk, side by side when the camera is positioned behind the desk, which turn into one (probably one on top of the other) when the camera is positioned in front. (00:07:00)
Continuity mistake: Hastings and Poirot are talking about the optimist friend. Once Hastings says "It bucketed down", he's holding the newspaper, and it stays pretty firm. Miss Lemon knocks, and the newspaper is now folding at the upper corner. (00:06:45)
Revealing mistake: When Japp points at the news on the paper about the mine stocks going up, in the close-up you can see easily that only the title and the enlarged text of the first 3 lines talk about the mine. The rest is sports talk. (00:33:55)
