Blooper

The St Leger scenes are a clever combination of newly-shot footage and archive material. However in the archive footage, the jockey of horse number 8 wears chocolate and blue hoops, whilst in the newer footage he wears red and green.

When the ABC railway guide is shown in close-up, sometimes the text "August" can be seen on the cover and sometimes this month space on the cover is blank.

The second victim worked at the De La Warr Pavilion in Bexhill, and her employer is interviewed and reveals that she had worked there for two summers. However this cannot be right as the De La Warr Pavilion only opened in December 1935 and the murders are set in 1936.

Much of the cast are travelling by train to Doncaster. However the train is hauled by Southern Railway locomotive, a type that would not be seen north of London in 1936.

Signs on platforms for railway stations are always aligned along the platform, so as to be readable from the train by the passengers. The sign for Churston is seen by Poirot and Hastings when they reach the top of the stairs, and it is perpendicular to the platform.

The programme features a number of excerpts from a supposedly contemporary "film" from 1936. The effect is strikingly well-done, except at the end of the film are shown the acting and technical credits; in a genuine 1936 film, these credits would have been shown at the beginning.

When Hastings and Poirot look up trains to Churston in their ABC, both the left-hand and the right-hand pages are identical.

In Doncaster, as Mr. Cust is getting up, to leave the theater, he turns to his left, but when, at the end of the movie, when the real murderer is revealed, and that scene is played, Mr. Cust is seen turning to his right, to leave the theater.

While this episode takes place in 1936, a poster for Bionda fragola (1941) is seen at the cinema. That film was released in 1941.

People are watching the film Ribalta nera (1939) which was released in 1939, yet this mystery is set in 1936.

Both the September 2, 1936 edition of The Star and the September 21, 1936 edition of the Daily Mirror feature stories referring to the Prince of Wales. In reality, there was no Prince of Wales at that time as the previous holder of the title, Edward VIII (later the Duke of Windsor), succeeded his father King George V as King on January 20, 1936.

As noted, the St Leger sequences contain intercut archive footage and modern shots. However, the archive footage is almost certainly from the early 1960s. Several male spectators are wearing no headgear, and those who do are wearing caps. There would be few hatless men in the 1930s, and most of the men would be wearing hats with brims (as they are in the 1990s recreation).

The August 29, 1936 edition of The Evening News refers to the Georgian nobleman Prince Alexis Mdivani as having been killed in a car accident in Spain the previous month. In reality, he was killed on August 1, 1935.

Cast members are seen arriving at Doncaster station. But it's not Doncaster station in Yorkshire, it's St Pancras station in London.