Visible crew/equipment: When the guy on the roof stands and takes aim at the window in preparation for Brian, the film crew are reflected in a window behind him. (00:13:00)
Other mistake: At the end, when Peter saves Mary Jane from the collapsing structure, he jumps up in the air and swings her to safety. However if you look at the web he is holding onto it is hanging down vertically. What did he attach the web to that was directly above him, the sky? Every bit of the structure around him was/had collapsed and the only thing remotely close to swing from was the cranes. Yet we see that was quite a distance away, so Peter would have had to shoot the web away from himself not above him. (01:47:50)
Continuity mistake: When they bring Marvin Nash to be tortured, his hands are cuffed behind his back. They start kicking him and his hands are then seen cuffed in front. Then, they switch back just a few moments later and his hands are back behind his back again.
Revealing mistake: When Santos catches fire and falls over on deck, the fireproof vest is very visible on his right arm. (00:46:05)
Continuity mistake: There are a couple of instances in the movie where the models do not correspond with the actual sets. When Klytus arrives at the Hawkmen city he lands near the top of the city. Yet in that very hall there is a pit with a deep void underneath. Such a room could only exist at the bottom of the city. Also, when the Hawkmen start to land on Ajax, its engine section appears to be missing. (01:10:10 - 01:14:30)
Revealing mistake: When the computer is being hacked and the password and/or code for the database is shown on the screen, most of the display is for an Autodesk printer driver. (01:39:00)
Continuity mistake: When everyone is searching upstairs and Miss Scarlet and Colonel Mustard start screaming, they all come running down. Yvette and Miss Scarlet have on flat black shoes, but right after the running shot is over, both are back in heels.
Continuity mistake: As Sy is developing Nina Yokin's birthday party negative the film canister shown has the green and white Fuji colors and layout. When Sy holds the processed negatives up to the light to view the exposures the film information along the side of the strip indicates the film is Kodak Portra 400VC. (00:06:50)
Continuity mistake: When Maggie starts cleaning up the flour, she hears a noise and looks at the three blue flowerpots, and there is a wooden chair right beside them. Then when it cuts to Maggie getting up, the chair is now about a foot away from the flowerpots. (00:22:50)
Continuity mistake: During the scene when Arnold carries the casket, a shot shows many bullet holes on its front side. Two shots later, these holes have disappeared. (00:54:45)
Continuity mistake: As Christine and Raoul race up the stairs of the Opera House, her hair is loose. By the time they come out onto the rooftop, it's partially pulled back in an elaborate fashion. She's never off screen long enough to have done that. (01:05:35 - 01:07:05)
Revealing mistake: In the scene where they're tumbling down the hill, Buttercup has a beard.
Visible crew/equipment: At the beginning of the movie, Sheriff Teasle escorts Rambo to the outskirts of town. As the sheriff drives off, the boom mike is visible in the reflection of the car's right rear passenger window. (00:07:30)
Factual error: When we see the burning 'DD' in Joe Pantoliano's glasses it is not a reflection. The DD should be backwards in his glasses. (00:26:55)
Visible crew/equipment: Watch for the boom when the cigar girl's Volvo boat swipes the building. It's on the top left of the screen on the widescreen version.
Visible crew/equipment: Bond follows the girl through the streets of Venice. The camera follows him with a track shot. Bond turns left, going into some kind of alley, and the dolly keeps going. The dolly, camera, and crew are reflected in a window for a second. (02:02:10)
Continuity mistake: After Bella awakes from the first nightmare, we see her Romeo and Juliet book on the pillow beside her. When Charlie brings in her presents the book is gone, but then reappears on the pillow between shots. (00:03:00)
Visible crew/equipment: When moving into their apartment Patrick Swazye kicks the statue to make it swing so they can get it inside. As they are looking at the statue, two moving men cross in back of them carring a mirror and as they pass you can see the director and camera crew in the reflection.
Deliberate mistake: Almost trivia, but not quite. When Mystique's looking through the guard files to find a suitable candidate, lots of photos flash up very quickly before she finds the guy she uses. Of note is that Bryan Singer pops up in guard uniform (with his own name), and so does someone called "Donner, L". This is most likely referring to Lauren Shuler Donner, one of the producers, and sex is specified as "F", but the photo is of a stubble-coated man. (00:23:10)
Continuity mistake: During the scene where the police first go to arrest Howard and John is deciding which door is the right one his plastic face plate is down and in the next shot it is clearly up. (00:10:55)