Goofs

48:00 The stopper is placed in the whiskey bottle twice, once from behind and then once from the side.

Miranda reads in a book that Findley is worth billions. In the time in which this movie is set, in Britain, a billion is not a thousand million but a million million. As such, there was nobody worth billions in the world, and a British book would not have made that claim about anybody.

British police do not routinely carry guns, especially not in the time this film supposedly takes place.

While the USSR did develop a Closed Circuit TV (CCTV) in 1927, it was very rudimentary and not available outside of the USSR. CCTV wasn't developed in the West until 1949. The ability to record video didn't exist until the 1970s. It would have been impossible for anyone to have CCTV that could record video in 1934 England, the setting of the movie.

The carriages in which the characters travel in to the island are of an American design. British carriages of the era would have been enclosed at both ends and would not have had steps down to the platform as British railway stations have raised platforms.

The film is set on an island off the coast of England, and the time of year is the fall of 1934. Yet the breakfast spread shows strawberries.

Strawberries would not have been available anywhere in England in the fall, much less an island where every single item has to be brought from the mainland by boat. Strawberries are a spring crop. It wouldn't have been possible to import them, either, not with the consumer goods market the way it stood in 1934.

The breeds of domestic rabbit shown in the shack were not developed until many years later. For example, the dwarf lop was not developed into the 1980s.

The external shot of the mansion could not be a British one from 1934. The stone is incorrect and the windows far too large.

Phillip says the whole situation is a charade but he uses the American pronunciation sha-raid. As a middle-class Brit he would have said sha-rahd.

When Miranda buys the new Agatha Christie novel she refers to Inspector Poirot. Hercule Poirot was a private investigator, not a policeman.