Continuity mistake: When Peter and Gwen finish dancing, a waitress passes by them. Less than half a second later, from a new angle, she's repeating the movement. And a frame after that, from a third new angle, she disappears from screen as if she hadn't started walking by.
Continuity mistake: After the armoured truck scene, Spiderman arrives at a roof top, sits down and is about to take his mask off, which is tight around the neck. When the angle changes, before the hand grabs the hood, it already appears loose around the neck.
Continuity mistake: When Venom explodes, from the front shots Peter covers his eyes and nose. From the back he appears covering his mouth and nose instead.
Continuity mistake: During the hanging cab scene, when Venom ties Spidey to a web. A shot shows his back naked. However, when Spidey kills the symbiote, Eddie is wearing a t-shirt.
Continuity mistake: When the model is about to fall, there's a view of the street and the huge traffic jam and chaos from before has disappeared. The cars are driving normally and there's no debris on the asphalt.
Continuity mistake: Before Sandman falls down to the sewer, he lets go a bunch of dollar wads. When he is free falling the money disappears.
Continuity mistake: In the middle of the film when Ursula tells Peter that MJ called back, when she first enters Peter's apartment he is sitting at the computer, look closely here, there is no framed picture of MJ standing against the computer, yet in the following shot a framed picture of MJ has appeared standing up against the computer.
Continuity mistake: When the symbiote is trapped around the metal bars, its wild movement produces air that moves Peter's hair. However, in a couple of shots his hair is still, turning stirred a frame later from a new angle.
Continuity mistake: In the scene where Brock and Peter are in Jameson's office and Brock is talking about how he wants a staff job working for Jameson, Jameson waves his secretary out of his office. He starts smoking his cigar in his left hand, yet in the following shot he is now smoking his cigar in his right hand.
Continuity mistake: When the crane strikes for the second time, the wide angle shows the photographer on the floor. Half a second later he is standing tall.
Continuity mistake: When MJ gives Peter the final hug, her left hand is around his nape. Cut to a back angle and the hand is away and starting to move to the nape.
Continuity mistake: When the office floor is collapsing, a wide angle shows all the of the furniture sliding down, except for a desk on the left. Seconds later, while Gwen is hanging by her fingers, dozens of chairs and desks keep appearing from nowhere, including the one that throws her away.
Continuity mistake: When Peter goes to Harry's house to fight him, between shots, Peter's hair moves from over his eyes to the side.
Continuity mistake: When the cop is walking on top of the truck, we can briefly see that the tarp is covering part of the back right side of the truck. In the next angle it's only covering the front right side.
Continuity mistake: When Mary Jane reads the critics reviews, the back shot shows her holding the paper from the bottom. The front shots shows her fingers on the middle top part.
Continuity mistake: In the scene just after Harry regains his memory and his father tells him "first we attack his heart", we see MJ at the door of her apartment, in the first shot you can see that her handbag is on her left shoulder but in the following shot from a distance her handbag is now on her left forearm.
Continuity mistake: Near the beginning of the film just after Peter has knocked Harry off of his jetboard, Harry falls onto the alley floor where you can see large amounts of puddles where Harry lands, yet in the following shots where Peter is trying to revive Harry, some of the puddles have vanished.
Continuity mistake: When Venom blows the cab's roof, there's a back shot of the cab from above and MJ is nowhere to be seen. The shot is clear and long enough to show the back seats. Furthermore, MJ is wearing a white shirt and, since it's night time, there's enough contrast to show that she is not crouching, nor hiding, but is simply missing from the CGI shot.
Continuity mistake: From a back shot, when Peter Parker is watching the screen with the promo about his life, the kids are standing still next to him. From the immediate front shot, the kids are arriving and taking positions.
Continuity mistake: During Venom and Spidey's final battle, the amount of tubes on the floor diminishes drastically between shots.
Answer: At one point in time, Sony was set to make "Spider-Man 4" with director Sam Raimi and stars Tobey MacGuire and Kirsten Dunst. However, Raimi was unable to find a script he was satisfied with after many months of working with different writers, and he was having issues with the studio attempting to force the film into a 2011 release date, which he felt wouldn't give him the time he needed to make a quality film. Thus, he and the actors dropped out and the studio instead opted to go ahead with a reboot, in the form of The Amazing Spider-Man.