Continuity mistake: In Uruguay, when the woman puts Christian Szell's folded shirts in the drawer, the camera pans toward the photographs on the dresser. There's an unframed photo of his brother Klaus in the closeup, but it's a different photo in the next wide shot. (00:38:25)
Revealing mistake: When De Niro gets shot in the neck, his bald skin cap wrinkles considerably when he presses the wound with his hand. Confirmed by make-up artist Dick Smith in the making-of documentary. (01:40:00)
Revealing mistake: A crowd of people are watching the filming as Harry sprays one of the kidnappers with a water hose. (01:25:49)