Niagara (1953) - 9 major mistakes

Continuity: When the Canadian motorcycle police drive up and speak to the boat keeper about George Loomis they're all in direct sunlight with no trees anywhere near them. When they leave several shots later it must be an entirely different time of day because shade from the trees across the street covers the entire set.

Continuity: Mr. Qua and the Cutlers walk away from the Loomis' room after talking to Marilyn. If you look closely the stonewall to the left of them is not in direct sunlight as it was a few shots earlier when they walked up to the door.

Continuity: When the Canadian motorcycle police drive up and speak to the boat keeper about George Loomis one is wearing a white shirt and the other a blue shirt. In the next close-up shot their both wearing blue shirts.

Continuity: George Loomis goes over the falls and Polly is safely on an island in the middle of the river with green trees on it. Several shots later the trees are purple.

Continuity: George Loomis tries to steal the boat and pulls the ignition wires straight out from under the lock. No one touches them but the next time we see them they're hanging differently.

Continuity: Inspector Starkey gets into the police car before Ray Cutler, who sits in the rear driver side seat as they pull away. Several shots later we see them again in a close-up chasing George Loomis and their positions in the rear of the police car have reversed.

Continuity: Two Canadian motorcycle police drive up and speak to the boat keeper about George Loomis, and a prominent tire mark is on the side of the road in front of the black car. The next time we see this spot as Ray and Mr. Kettering run to the boat it's not there.

Visible crew/equipment: George Loomis talks to Polly in the boat and looking outside the window it's easy to see that there's no island in front of them. A few shots later it's obvious that the island is superimposed on the falls.

Continuity: George Loomis throws a lit cigarette at the ash tray on the table to the right of the door as Polly Cutler knocks. We see the cigarette smoldering on the table but two shots later after she enters we see the same spot again and it's gone without anyone going near it.