Other mistake: After they shoot each other's hats and are in the hotel room, Monco says who goes around with a contraption like that (referring to Mortimer's gun). Mortimer says that contraption almost sent you to your grave. In the heat shooting scene Mortimer uses a regular pistol, not the contraption.
Continuity mistake: When Manco is dealing the cards, the position of the cards dealt to Cavanaugh change over and over with each card dealt. A coin is visible on one card dealt, then it is gone on another deal. Manco's stack of cards he deals to himself also change from a neat pile to a slightly askew pile.
