Other mistake: When they're roping the mustangs, the "stallion" doesn't have the genitals of a stallion.
The Misfits (1961)
1 mistake
Directed by: John Huston
Starring: Clark Gable, Marilyn Monroe, Montgomery Clift, Thelma Ritter
Roslyn: If I'm going to be alone, I want to be by myself.