The setting of the film is August 1935, yet Poirot and Hastings are playing a game of Monopoly on the U.K. version of the board game. Monopoly first appeared in the U.S. in 1935, but the British edition with London names didn't come out until 1936.
-- When Japp is in conversation with one of the radio cars, at one point the detective in the car says "Control to Unit 7". He is Unit 7, not Control. --
While it may appear that the character has confused his role, in actuality he is NOT saying "Control to Unit 7," rather he is saying "Control, Unit 7" as in "Control, [this is] Unit 7" or "Control, Unit 7 [here]".
While it may appear that the character has confused his role, in actuality he is NOT saying "Control to Unit 7," rather he is saying "Control, Unit 7" as in "Control, [this is] Unit 7" or "Control, Unit 7 [here]".
During the surveillance operation, the blue taxicab Dyer gets into has different number plates on the front and the back.
When you first see the St James Hotel the sign on the pillar is obviously a paper sign that has the name of the hotel printed on it.
At about 49:00. When shown the check from Lord Avebury to Poirot for Five Hundred Pounds, the sum is written as "500.00". In 1935, British currency was still expressed as Pounds, Shillings, Pence: the sum is correctly written only for the decimal currency introduced in 1971.
The story is set during the autumn of 1935, yet Poirot and Hastings play Monopoly on a game board with London locations. The first London edition of the game was not published until 1936. Also, the Monopoly money they use has only numbers, while the actual money for the first British edition had numbers with pound symbols.
The date Han Wu Ling signs in the register at the beginning is the second of august 1935. However, Monopoly, which Poirot and Hastings are playing at the same time, was not released in Britain until 1936. The American version was not even invented until December 1935 making it impossible that Poirot and Hastings could be playing the game in August.
It is stated that Wu Ling left the hotel around ten and was never seen again. He did not leave the hotel, he was sent to the lounge to see a man and disappeared with his lit cigarette left behind in the ash tray.
Lord Pearson tells Poirot and Hastings that a lump of ore can be refined into "top grade twenty-four karat silver". But the karat is a unit of purity for gold, not other precious metals. Silver purity is measured in parts per thousand, with pure silver being 999.
Mr Ho is conversing with another Chinese man before Japp comes in. Ho's friend concludes with, thank you, in Vietnamese.