Goofs

When Bulldog and company are flying from France to England, they take off in a high-wing monoplane. However, when we see the shot of them landing, the plane is a low-wing monoplane.

Apart from the opening stock shots of London - including one of Scotland Yard - the whole feeling of the outdoor scenes is American. The shots of the train supposedly being chased by Drummond are of American trains. When Tenny is following the van (despite it being right hand drive) the streets they pass through and the open countryside are all American in character; including the unfenced, unpaved roads. The shot of Big Ben at 8.45 pm is accompanied by a single high-note bell stroke, instead of at least part of the Westminster chime for the three-quarters of the hour. After a stock shot of British motor fire engines racing through London, the three outside Goodman's house are steam-driven pumps from the horse-drawn era. Sir Raymond's surname Blantyre is consistently pronounced as Blantree. In 1938 Blantyre was a town in Scotland, also a major town in Nyasaland (now Malawi), and pronounced to rhyme with 'fire'. A police constable says Drummond's car had been standing by a fire hydrant all night. In America that might be illegal, but not in England.

The sign at the Airport is incorrectly spelled "Aérodrome du Macon" in French, when it should read "Aérodrome de Mâcon".

A policeman complains that Drummond has parked by a fire hydrant, but in the UK, hydrants are below the surface and there is no law against parking by one, unlike in the USA .

When the fleeing truck hits the lamppost, it can be observed to have not been anchored to the sidewalk, but was supported upright by two crossed boards at its base. The light, after being hit, continues towards the camera and strikes it - as a few unedited frames reveals.

When the motorcycle is chasing the truck, at one point both are driving on the right side of the road, despite the fact the scene is set in England, where they drive on the left.

When Dr. Botulian arrives at Drummond's apartment to ask for the letter the second time, Drummond refers to him once as Professor Goodman.