Continuity mistake: During the battle with Green Goblin, when Gwen Stacy is falling through the clock tower, there are dozens of gears and other pieces of various sizes falling with her. However, when she lands, only a few small gears and pieces land alongside her - all the other debris that were falling have seemingly vanished. (02:01:20)
Suggested correction: That part of the scene is SO dark that it's really hard to tell; they do show some gears and pieces land after she does and there are some gears and pieces next to her when he walks to her. I wouldn't say there's none, but I'd say it does seem a disproportionately low amount considering how many giant gears were falling.
Given that even you admit in your correction that the number of gears seems disproportionately low (which it is - we only see a few small pieces landing when there were dozens and dozens of pieces in different sizes falling), I think amending the wording through a word-change is a better option than trying to correct the mistake itself. Because there is still a mistake here. Going to go ahead and do that after I post this response. (Might take a few days to change, though).
Continuity mistake: When John first meets Marcus in the cemetery, John's umbrella changes from a standard 8 rib when lowering the coffin, then a 22 rib close up, then back to 8 ribs in a far shot of the two men shaking hands. (00:04:15 - 00:05:45)
Continuity mistake: When Cathy is duct taped in the SUV the tape is around her body, but when the SUV crashes she gets out and there is only duct tape around her wrists.
Continuity mistake: After Aaron extracts the capsule out of his butt, when he shows it to Dave he is either holding it pointed upwards or horizontally, depending on the shot.
Continuity mistake: When Justin is disguised with the dread locks, one of the body guards gets into a fight with him. Justin is punched hard in the face in slow motion, the impact of the fist shown to hit below Justin's cheek on his jaw. Yet the next day Justin has a huge red mark above his cheek on his temple.
Continuity mistake: When Quicksilver duct tapes the guard in the elevator, the tape changes when Quicksilver and Magneto come back. For example, when they get back, the tape on the chin is now tucked under tape strips and there are more spaces seen.
Continuity mistake: Federov is pointing a Wather at a kneeling Mira. In the next shot his gun switches to a Sig-Sauer and then back to a Walther. (01:12:55)
Continuity mistake: In the scene at the college where Callaghan asks to look at Hiro's Megabot, Callaghan's shirt is blue, but when he holds out his arm to take Megabot, his shirt sleeve is red. Later on he is wearing a red shirt at the SFTT. (00:13:30)
Continuity mistake: Towards the end after Dracula bites Mehmed on his left side of the neck, when he lies on the floor there is not blood on it.
Continuity mistake: In the scene where they're leaving the school, there are a ton of cars behind them on the highway and then all the cars just disappear.
Suggested correction: Our heroes are in the last bus. There are a few cars exiting behind them, but you see at least one of the cars pass the bus and get ahead of it. In the first aerial shot of the highway, you can only see two cars behind the last bus. When the tower falls, it lands just behind the second-last bus, cutting off 3 cars, then our heroes' bus, then the Titus and another 2 cars. At no time is there a line of cars behind the last bus that disappears.
Continuity mistake: When the Dark Aster enters the atmosphere at the end of the film, its wings untwist as it descends, in most of the scenes afterwards and the hologram the ship's wings are still twisted, then later during the battle they untwist again.
Continuity mistake: Thomas takes the blade of Theresa at the top of the tower. When he does, his grip on the blade changes position and the hand changes too. (00:55:30)
Continuity mistake: When the guy robs the cashier at the store where he works, the guy leaves the store and there is a car waiting by the curb. He gets into the passenger side and you see the car drive off. But when it shows the back view of the car as it is driving away, there is only the driver and no passenger.
Continuity mistake: Halfway through the film, when the turtles ask April to meet them on the rooftop, she is wearing a plain black top under her yellow jacket. In the next scene when the turtles have taken her to their lair, she is now wearing a light grey shirt with a symbol on it.
Continuity mistake: After cutting through Black Manta's gun, Aquaman then slams Manta in the face with his trident and knocks him down. As he is twirling his trident in victory, you can see his belt and its design. But then it cuts to a close up of Aquaman and suddenly his belt changes in design with the bar in the middle disappearing and the black of his pants extending further up onto his orange shirt in the belt area. (00:03:50)
Continuity mistake: When the car with Alice goes over the cliff, and when she then exits, she is wearing shoes. When she awakens and begins climbing (and afterward), she has none.
Continuity mistake: During the gunfight in the arms dealer's hideout, Robocop enters brandishing his futuristic 'M2 Battle Rifle' which then immediately changes to an MP7 in the next shot. This error gets particularly blatant during the following shots from his POV, where he's shown still firing the M2 in his HUD, only for the scene to immediately cut to show him firing the MP7.
Continuity mistake: Hercules and Tarak are sitting together talking and Hercules pulls out the necklace that his lover gave him as he reassures Tarak that he will get them to Greece. In one shot he is looking down at it in his hands, then the next shot his head is suddenly leaning back against Tarak. (00:37:45)
Continuity mistake: Briareos' VTOL fires all of its forward missiles twice. (The forward missile bays have distinct markings in the form of a set of three white rectangles at each side). (01:15:26 - 01:16:40)
Continuity mistake: Just after the captain's death, a close-up on Bill's watch shows its date as '11 07'. At all other times, it says '1 18'.