At 1:29:38, there is a two-second shot of Indy reaching for the lead horse of the runaway wagon, but it is ten seconds early, as the next shot shows Indy still behind and then overtaking the wagon.
The story takes place in 1920. The song sung by the chorus at von Stroheim's pool, "O Fortuna" by Carl Orff, was not put to music until 1935, although the lyrics are about 750 years old.
The story takes place in 1920. In the opening scene, young Indiana Jones is sitting in a movie theater, watching the chariot race from Ben-Hur: A Tale of the Christ (1925), which wasn't released until 1925.
The story takes place in 1920. When Indiana has left the cinema and is walking the streets of New York, on his way to Universal Studios office, there is a big sign hanging from the side of a building with DEWALT written on it, but the company of DEWALT was not founded until 1924.