Continuity mistake: After Donald Sutherland parachutes into England, he walks across a cow paddock towards a gate. As he climbs over the gate, you can see there are no cows to the left of him along the fence but in the very next shot, you can see a line of cows along the fence which weren't there in the previous shot. (00:39:55)
Continuity mistake: When Billy and Chris are placing the pigs blood above the stage, Billy spills three drops of blood onto Chris' torch, but in the next shot there is only one drop on it. (00:46:00)
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)
Visible crew/equipment: During the final fight, a steady cam operator with a white shirt and black straps around his body is seen during several wide angles. This is not a TV camera, it is a film crewmember. The Director even admits to it in the audio commentary on the DVD.
Visible crew/equipment: When Peck is falling down the stairs with the kid, you can see the back pad through his coat.
Continuity mistake: When Mrs. Hallet goes to retrieve the rubber seals from the cellar, she opens the trap door and the diagonal wood creates "Z" bracing; but in the next shot, as Hallet heads down the stairs, the diagonal wood cross brace is now attached to the door in the opposite direction, making a backwards "Z" bracing. None are flipped shots. (00:27:30)
Continuity mistake: When Christella is slapped by the possessed Ike, her pose changes between shots.
Revealing mistake: A crowd of people are watching the filming as Harry sprays one of the kidnappers with a water hose. (01:25:49)
Continuity mistake: In the scene where the German and Jewish drivers are arguing, there is a corner establishment visible in the background with a sign that reads "wash." In certain shots, a "going out of business" sign is visible in the storefront, while in other shots, with close-ups of two passers-by observing the argument, the same corner establishment is visible without the "going out of business" sign.
Revealing mistake: When Mrs. Schmauss is on her bike, holding a wheelie and spinning after being almost hit by the car, while the other bikers are passing by, a support holding the bike up is visible. (01:29:01)