Other mistake: In all of its appearances, the British flag (also known as the Union Flag and the flag of the United Kingdom) is wrong. The flag's X-shaped red Cross of Saint Patrick is shown as (a) wide, and (b) centered on its white background, whereas on the actual flag, it is (a) thin, and (b) not centered on its white background, but rather off-center in a counter-clockwise direction.
The African Queen (1951)
1 other mistake
Directed by: John Huston
Starring: Humphrey Bogart, Katharine Hepburn, Robert Morley, Peter Bull
Revealing mistake: When the boat is supposedly surrounded by a swarm of flies, they're really just relatively few flies trapped between two panes of glass in front of the camera lens. Evidence: whenever the camera moves, the "swarm" moves with it against the background, and you can even see some of the insects walking on the surface of the glass.
Rose Sayer: Mr. Allnut! Mr. Allnut, you may come in out of the rain.
Trivia: Humphrey Bogart won his only Oscar for his performance as Charlie Allnut in this film.