Other mistake: When Marge is being questioned, before she says 'If you don't have anything nice to say, then don't say anything at all', there is a shot over her shoulder looking at the blue haired lawyer. Not only is he (the lawyer) there directly in front of her, but he is also sitting on the bench with Burns. In all other shots his chair is empty as it should be.
Continuity mistake: After Candy and the stunt man quit the movie, Mr. Maxwell says he has to withdraw his job offer to the gang as it's too dangerous. As the gang is shown, Scooby is sitting in front of Shaggy and Fred. It cuts to a close up of him as he gets excited about this, and suddenly Fred and Shaggy have vanished. (00:06:10)
Other mistake: After the turkeys start attacking in "The Running of the Turkeys", Mr. Fishoder and his brother start running. In that clip a Turkey pops out the side of a guy's head. Look in the mid lower right side. Looks like a design error. Pretty big error, no slow down needed to see it. (00:05:20)
Continuity mistake: The gang investigates the trail of limestone to a manhole in the middle of the street, with nothing around it. But when Daphne is putting on her "Wallowing galoshes" boots, somehow a small brick wall just materializes in the middle of the street for her to sit on - and then vanishes a couple shots later. Not just the fact that it appears and vanishes between shots, but that there is a random brick wall in the middle of the road. (00:05:10)
Continuity mistake: When Palpatine and the others exit the elevator, a rear shot of their group shows that one trooper holds his rifle, but the other is missing his rocket launcher. But when seen from the front again, this trooper has the very obvious launcher hanging from his shoulder, behind him. (00:40:00)
Continuity mistake: When Fred is reading his letter about his position being accepted at the Stone Valley Inn, you can see Wilma is sitting in the chair next to him, but in the next shot the chair is empty and Wilma is nowhere to be seen, then she reappears in the chair.
Continuity mistake: When Joker zaps Wonder Woman and her mother, they are both standing in front of their thrones and fall forwards. But when Wonder Woman stands back up, her mother, still unconscious, is suddenly off to the side and behind the thrones. (00:11:35)
Continuity mistake: When Tony says he has to stop the train from hitting the building’s power generators, the camera zooms in on a train car at the entrance of Stark Tower by the tracks that has the generators on it, and there are two Stark International employees standing on the balcony beside it dressed fully in white. Only a couple seconds later, Tony flies down there to cut off the train, and suddenly the two guys have vanished. (00:18:00)