Revealing mistake: In the scene where Ashley is brought back wounded from the raid where Scarlett's husband Mr Kennedy was killed, Melanie grabs an oil lamp to follow the man carrying Ashley to the bedroom and you can see an electrical cord hanging down from it. (00:50:45)
Revealing mistake: When the carriages arrive at Twelve Oaks they turn transparent halfway down the driveway. (00:17:15)
Revealing mistake: When Scarlett finds Twelve Oaks completely destroyed, the carriage in the background is not real. As Scarlett walks toward the staircase, both the carriage and Prissy are not real, it is just a picture that has been painted to make it look like they are sitting there.
Revealing mistake: After Frank Kennedy's death Scarlett is sitting in her room, "mourning" and drinking. When she hears Rhett's carriage she goes to the window. In this moment you see shadows, either from crew members or equipment, cast through the room, especially visible on the bottle on the table. There is also some funny shift of the backdrop outside the window. (00:55:35)
Revealing mistake: When Scarlett runs out of the Wilkes's house calling for Rhett after Melanie dies, she bumps into a pillar that supposedly helps support the house/porch. The pillar wriggles quite violently at her touch, revealing it as a simple stage prop and not part of the house.
Revealing mistake: There is a very short scene in the second half of the film where Mrs Meade and Dolly Merriweather are sitting at a tea table gossiping about Scarlett's behaviour. There is a teapot in the middle of the table, and Dolly Merriweather is sitting behind it. Yet the teapot is casting a shadow on the wall and Mrs. Merriweather isn't.
Revealing mistake: After Rhett tells Scarlett that he doesn't give a damn, she's just inside the front door and places her hand on leading edge of the door, which moves when she touches it to support herself.
Revealing mistake: When Rhett picks up newborn Bonnie from her bassinet, you can see that he picks up a doll, not a real baby.
Revealing mistake: When Bonnie has her fatal horse accident and breaks through the hurdle you see that the bars are pre-cut.It's a bit unrealistic anyway that they would break at such a soft impact - they should fall but not break. (01:39:45)
Revealing mistake: After Frank Kennedy's death, Scarlett is drinking in her bedroom, when she spies Rhett arriving outside her window. She then races to the mirror to brush her hair. She does not actually touch her hair with the brush strokes, probably so as not to disturb her hair, which had been specially styled by hair and makeup staff.
Chosen answer: It looks to me like a bird flying from the tree to the ground. Nothing controversial there and no reason to edit it out.
ChiChi