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 Nino goes to 'Les deux Moulins' for the first time, we can see Amelie writing the menu on a glass right behind him. A few shots later, we see the glass again and the handwriting is quite different. That's easy to see if you look carefully at the 'd'. Later on, we see the glass once more, and the handwriting has changed again. (01:32:55)
Continuity mistake: When Russell Crowe first pulls in front of Hank Azaria his car's quite angled on the road as he gets out. When we see a wide shot after they finish talking, the car's now much straighter without anyone having gone near it.
Continuity mistake: When D-Fens is in Whammyburger, there are two spots on the right shoulder of his shirt that keep disappearing, reappearing, and changing positions. (00:41:15 - 00:44:30)
Continuity mistake: When Vassili and his two friends go out to trap König by shooting telephone repairmen, their rifles are covered by hessian, when they are shooting the repairman the guns are uncovered, and when Koulikov and Vassili are on the way back and jump across the gap in the buildings their rifles are covered again.
Continuity mistake: After nana picked up Will's kids and Will Smith is lying in the back of the car, look closely at nana's seatbelt. In the first shot it's on, in the next shot she doesn't wear it anymore and in next shot its on again.
Continuity mistake: As Arnie runs after Leigh at the drive-in, he arrives under the awning with his hair slightly wet, but still rather full-looking. But in the next close-up, it's soaked flat onto his head. (00:45:40)
Continuity mistake: When Ricky comes home and starts to watch TV with his parents, on close up shots of the TV there are pictures and a vase on top of it, but when they show shots of Ricky and his parents, they mysteriously vanish. (00:27:55)
Continuity mistake: In the opening scene, Andy is seen eating a bagel, then the shot changes and she has no bagel, but when she goes down the stairs into the subway the bagel is back in her hand.
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)
Continuity mistake: In Beth's death scene check the arrangement of pillows under her head. It changes several times before and after she dies. (01:32:45)
Other mistake: When the Pirates are arrested in Nineveh, another soldier walks up to Jonah and knocks him out with a fish. When this happens, Jonah is wearing the Cheese Curl hat. When he comes to on the Slap of No Return, he is wearing his turban again. Would the soldiers change his hat?
Revealing mistake: When David pushes the pallets onto the car, it's obvious that there is no-one inside. Similarly, when he uses the forklift to pick up the car a few shots later, we see inside the car and there is only a badly constructed dummy-type object in the back seat, and no real people. Even if they had bent down, they should still be visible. (00:09:00)
Visible crew/equipment: When Michael is about to open the door where he finds the janitor, there is a close up shot of the door handle where you see the reflection of three studio spotlights. (00:21:20)
Visible crew/equipment: When Robinsons Crusoe's boat breaks lose, you see a shot of a beach, and in the lower left corner there is some kind of information board. (00:59:50)
Visible crew/equipment: When Henry helps pull Mark onto the treehouse at the beginning of the film, if you look very closely to the left you can just make out a crew member dressed in black helping him on to the platform. The crew member then ducks back under the platform.
Continuity mistake: In the scene where the Monte Carlo is battling with the Camaro, they go off road into a field. During a certain shot, the Camaro has to jump a hill and it goes airborne. While it's airborne, you can see the entire front end is destroyed. However, after it lands, you can see the front end of the Camaro is in excellent condition and it remains intact for the remainder of the film. I would guess that they used at least two Camaros for the film. (00:26:10)
Revealing mistake: In the final scene when Annie and Sam are exiting the observation deck coming towards the elevators, the New York skyline backdrop which should be visible behind them is missing, and the entire sound stage wall can be seen beyond the observation deck safety railings instead. 'Although the exterior and lobby of the Empire State Building, 350 Fifth Avenue at 34th Street, are the real thing, a slightly larger replica of the Observation Deck was built in a hangar at Sand Point Naval Base on Puget Sound just northeast of - where else? - Seattle.' https://www.movie-locations.com/movies/s/Sleepless-In-Seattle.php. (01:39:35)
Revealing mistake: The film was rushed to theaters, leaving a few mistakes which Universal fixed. In the original cut, toward the end, Judi Dench's human hand is visible, complete with her wedding ring. This was fixed for the re-release.
Visible crew/equipment: When they return to Enterprise after their successful mission, Iceman points and shouts, "You!" at Maverick. In the shot facing Maverick as he turns his head, the reflections of the camera and large reflector screen are visible on Maverick's sunglasses. Also, note the lack of a crowd of people behind Ice in the reflection. (01:40:45)