Continuity mistake: When Annie is entering her home in London, she puts her hand on the doorknob and pushes the door open. In the next shot when it shows the entryway with the door opening, there is no doorknob.
Continuity mistake: In the opening scenes when you see the limo pulling up to let Annie and Martin out you see the pavement to the right of the limo has a lot of sunlight on it. When they get out and are standing on the pavement, the sunlight is gone.
Continuity mistake: When the twins are standing on the steps of the isolation cabin, talking about their familes, Hallie, one time is not looking at Annie - her eye-line for the special effect is off.
Continuity mistake: After Annie first meets Meredith (playing Hallie), when she's sitting in the red water floater, her necklace goes from tucked inside her bathing suit to out, then to in again.
Suggested correction: There's no mistake here. Hallie's necklace barely reaches the top seam of her bathing suit. It could easily slip halfway in and halfway out on its own.
Continuity mistake: When Hallie (posing as Annie) arrives in London, she is seen sitting on the left seat in the car when she's on her way home, passing by the various spots in London. However, when she reaches home, she is sitting on the right side of the car. Unless she was sitting alone, this is not logical as Martin was sitting together with her at the back of the car.
Continuity mistake: During the scene when Hallie and Annie are seen lying next to each other, Annie's ponytail goes from in front of her to in back in some shots.
Continuity mistake: In the opening scene, they show the lake and the little sign that says Camp Walden. There are boats under a roof top right in front of the pier. But in the scene where they show Annie jumping into the lake the boats are in a different location and the roof top is gone.
Continuity mistake: When Marva Kulp Sr. is sliding into the cabin, the girl on the right side top bunk is slightly under the sheets, and the girl on the bottom is sitting with her legs out. When the camera cuts back to the whole cabin, the girl on top is lying on top of the sheets, and the girl on the bottom is under the sheets.
Continuity mistake: When Hallie is posing as Annie and is going to her mother's house for the first time, a piece of her hair is obviously sticking out on the side of her ear (It's very noticeable). When she gets to the front, and the camera angle changes, her hair is all perfect without any hair sticking out.
Suggested correction: There's no mistake here. It's just the wind blowing her hair a little.
Continuity mistake: When Hallie and Annie are fighting over the lights being on or off, their light switches should alternate from flipping up or down. Annie does so, but when the camera shows Hallie flipping her switch, she always flips it down.
Continuity mistake: When the father exits the pool his wet hairstyle changes in every single shot.
Continuity mistake: When Hallie arrives at the airport, Martin has a bouquet of flowers for her. He never hands them to her, but suddenly she has them and sets them down in order to do the handshake.
Continuity mistake: When Hallie and Annie drag Meredith into the lake when she's asleep on the air mattress, the color of the air mattress is dark green. When Meredith wakes up with the bird on her chest, all of a sudden the air mattress is a two tone khaki color. When Meredith stands up on the air mattress in the next shot on the lake, the air mattress is now another shade of green.
