Revealing mistake: At the end, there is a group of people with their backs to the camera, facing & waving to the Fantastic 4. As the F4 fly towards the camera and out of the shot, the crowd turns to continue waving to them. One small boy in white remains facing the wrong way, still waving, until another child grabs the back of his clothes & turns him to face the right way.
Visible crew/equipment: When Von Doom puts his mask back on the camera turns around him and the camera shadow is visible on his cloak.
Continuity mistake: When the helicopter plummets into the wedding terrace, its nose is either pointing the right side or the left, depending on the shot. No continuity at all.
Revealing mistake: When Johnny and Reed are talking about the bachelor party in the lab, they keep moving from one side of the table to the other: One side has a green book, the other a red one. Note the books behind Johnny and you'll notice by the colour and the reversed text that the shot's been flipped.
Revealing mistake: In the beginning, when we see the sailor fall over the side of the boat onto the ice, watch the closeup first shot when he sits up - it's a (quite poor) green-screen shot with an image of icy water stuck in behind the actor. The ice has absolutely no sense of depth, the lighting on the background doesn't quite match the actor, and it doesn't match the following few wide-shots when the background is computer-generated.
Continuity mistake: When Johnny breaks the news to Ben about Reed and Sue leaving the group, as Alicia says, "You can't be mad at them for doing what makes them happy", in first shot, her arms are down, but in the next shot, she's holding her hand underneath her chin. (00:39:10)
Audio problem: When the Fantastic Four first meet Victor Von Doom, Doom says, "Now let's be clear about this, shall we? I hate you". In the next shot, his head is seen from behind, but if you look closely, you can see his jaw and face moving as if he were talking, but nothing is heard. (00:45:00)
Continuity mistake: During the battle in London, when Mr. Fantastic is holding Invisible, her hair moves wildly. A shot later, her hair is suddenly trapped under his arm and just a few locks move, though mildly. (01:21:20)
Continuity mistake: When the Silver Surfer passes by Egypt, a man with a turban has an old woman on the left. When the shot changes she's standing behind him.
Continuity mistake: In the airport, the woman with the pony tail by Torch having pictures taken is either next to him or away with a group of girls, depending on the shot.
Audio problem: After the Surfer flies by the wedding, Johnny takes off flying after him and at one point says "Man he's fast" while his face is on camera. His lips never move while saying this.
Continuity mistake: When the helicopter is being stopped by Susan, the bridesmaid's hair moves wildly, yet when the chopper gets closer and is about to kill her, her flowers and hair barely move, despite being inches away from the tail rotors and rotor blades.
Visible crew/equipment: Lighting screens are reflected on Johnny's glasses when he enters the disco.
Continuity mistake: In the disco, when Thing, Johnny and Reed walk in, Reed and Johnny suddenly stand closer together between shots.
Continuity mistake: When Reed is in the plane and places the briefcase, the grip on the handle changes between shots.
Continuity mistake: When the movie starts, Reed and Susan are in an airport, with a couple of stewardesses walking behind them. When the shot changes, a young woman has replaced them, yet a shot later they reappear behind.
Visible crew/equipment: When Torch is in the Black Forest, watching the crystal ball, 4 big light screens are reflected on it.
Continuity mistake: Thing, Johnny and Reed are at the disco. Johnny steps forward and Reed grabs him and says "We had a deal". A frame later Johnny is not two meters ahead but aligned with Reed.
Continuity mistake: As the Silver Surfer and the Human Torch fly down the face of the sloping Grace building, traffic on 42nd Street, below, can be seen moving to the right. When they hit the street level, traffic direction has reversed relative to the building. The number of lanes visibly reduces from 6 in the above view (2 parking lanes, 2 traffic lanes in each direction separated by a double yellow line) to 4 at the street-level view. This would also qualify under another category, as 42nd Street traffic is two-directional. The first, high angle shot from above correctly depicts the actual conditions on the street. (00:29:25)
Continuity mistake: Johnny chases the Surfer, who surfs down a building and shatters its windows and facade, yet none of the debris fall or even appear on the street in the next shots.
Suggested correction: Not necessarily a mistake. Little kids can have a hard time keeping track of/focusing on things. I know little kids that have a hard time looking in the direction of the camera when their picture is being taken.
Phaneron ★
There's a difference between not looking at a camera when you don't care about having your picture taken and being able to follow superheroes that pass you, especially if you're waving at them. The reason it's a revealing mistake is because everyone involved had to pretend superheroes were passing them and the kid didn't know when to turn.
Bishop73