Continuity mistake: When Spider-Man is being gassed by the Green Goblin, the mouthpiece of the Green Goblin's mask is open, and Osborne's lips are visible moving as he speaks to J. Jonah Jameson. Later in the scene where Spider-Man fights the Green Goblin in the burning building, a close-up of his mask is shown again, but this time there appears to be some kind of black mesh screen in the mouth of his mask.
Suggested correction: It's never fully open, it's just easier to see through the mesh in certain lighting.
Continuity mistake: At the Unity Day Festival, when Goblin says "Impressive!" and kicks Spider-Man away, watch closely. Goblin goes from standing on top of a bare ground to standing on top of some sort-of tarp instantly between cuts as Spider-Man hits the first table.
Deliberate mistake: During the fight at the Unity Day Festival, at one point Goblin is confronted by some cops and beats them up. Watch closely... you can tell that the first and second shots are just different takes of the same stunt from a different camera angle. Goblin's movies are exactly the same (except slightly faster in the second shot), and you can also tell it's the exact same two cops he's hitting. They tried to artificially lengthen the scene by showing two slightly different takes of the stunt.
Continuity mistake: During the World Unity Festival, after the balcony begins to collapse, Mary Jane hits the railing and a support falls from it. The support reappears and stays until she falls.
Audio problem: The wrestler's, wheeled out prior to Peter wrestling Bone Saw, mouth doesn't match the dialogue as he's speaking.
Continuity mistake: When Mary Jane falls off the balcony she falls sideways except for a shot of her falling face down. Shot changes and she is falling sideways again.
Continuity mistake: When Peter wakes up the day after he was bitten by the spider and goes to the living room doing a little "stunt", Uncle Ben immediately turns to him, but in the next shot he makes a forward movement as Peter falls on the ground after the stunt.
Continuity mistake: When Peter tries his first web swinging on the rooftop, the sky turns from sunny to cloudy between shots.
Continuity mistake: When Flash is hit by the tray with food he raises his arms in disbelief. A shot later his arms are lowered and he repeats the previous movements.
Continuity mistake: When the movie begins and all the students enter the lab, Mary Jane's boyfriend nags her and she moves her arm to her shoulder, then lowers it. In the following shot her arm is raised and she is lowering it again.
Continuity mistake: When Osborn is getting ready to radiate himself at his laboratory, he throws his clothes on the floor. Their position differs between the first and second shot.
Continuity mistake: When Peter leaves Jameson's office after becoming a freelancer for him, Jameson closes the door, and at the end of the shot, the door is half-shut, but in the next shot, the door is completely shut. (00:58:45)
Continuity mistake: The day after Peter gets his powers, while he follows Mary Jane to the school, the sun changes between shots.
Continuity mistake: When Peter is testing the web on the crane, his fringe swaps between messy/ brushed /windy / still between frames in no order whatsoever.
Continuity mistake: When Osborn is drinking whiskey and hears his inner voice, is about to see the African masks and before watching himself in the mirror, his fringe swaps from messy to brushed.
Continuity mistake: When Osborn is laid on the stretcher about to enter the vault, the cables by his right shoulder change positions between shots.
Continuity mistake: When Aunt May opens Peter's sleeve to show his wound, the opening differs between frames.
Continuity mistake: During the famous kiss scene, Mary Jane's hair keeps swapping styles between shots. It changes between hairless cheek then hair on cheek, and soaked and straight to curly hair.
Continuity mistake: When Aunt May is praying, right before being attacked by Goblin, the portrait moves closer/ further away from the quilt between shots.
Continuity mistake: This is a little hard to explain. During the Unity Day Festival, after Goblin beats up the cops, the shot cuts and he turns around to face Spider-Man, who lands in front of him. The problem? He was facing the same direction as Spider-Man in the previous shot (you can tell from the background), so it makes no sense that he has to turn around when the camera cuts.
