Revealing mistake: When Norman's assistant is securing his head in place in the machine, you can see a reflection of the green screens in his glasses.
Continuity mistake: When Peter tries his first web swinging on the rooftop, the sky turns from sunny to cloudy between shots.
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)
Revealing mistake: When the car jacker who stole Uncle Ben's car is being chased by the police, they seem to be doing a high speed pursuit. However when the car goes over the corner and demolishes a stand, a cut shows the inside of the car. The digital speedometer is reading 15-17 mph, hardly much of a challenge for the police to catch.