Visible crew/equipment: When Peter wakes up and discovers he can't see through his glasses, you can see a phantom hand on the left sliding out of view in the mirror. This happens the last time Peter tries to see through his glasses. It's not a reflection of his hand due to the angled edge - it's on the main part of the mirror. (00:18:05)
Other mistake: During the shots of newspapers with articles about Spider-Man, if you look closely at the shot of the newspaper article just before the shot of Spider-Man putting on his mask, the second column is repeated in the fourth column - easiest to spot is "NYPD spokesperson, Sean Young..." appears twice. (00:52:55)
Continuity mistake: When MJ kisses Peter in the cemetery, his head is leaning towards his left, and in the next shot, his head is leaning towards his right. (01:53:10)
Continuity mistake: When Peter accidentally flings the tray of food on Flash it hits him on the left shoulder but when Flash stands up the stain temporarily jumps over to his right shoulder. (00:23:19)
Continuity mistake: When Peter is trying to talk to Mary in the cafeteria you can see behind where he is standing there are numerous people and tables between him and the back wall. Peter then sits down and in the very next shot his table is one table away from the wall behind him. The shot may be lower but is from the same angle as before. (00:21:35)
Trivia: At the festival when the Green Goblin throws his grenades, before the shot of Parker, you see Stan Lee (creator of Spider-Man). He was supposed to pick up the little girl that he pushes to safety, but due to his age, after several takes he said if they wanted him to pick her up, they were going to be there all day. (01:04:10)
Continuity mistake: When Peter shoots webs around his room and hits the rocket over, all that is on the nightstand is the cool light bulb lamp, the picture and the Dr. Pepper can. When it flips back to the nightstand again you can see some weird green alarm clock next to the overturned picture. (00:33:15)
Continuity mistake: When Peter is just getting to the science lab at the beginning right after his friend gets out of his fancy car, if you look at the extras walking behind the two, you will see a bright red haired girl walking by, going towards the building, but when the camera focuses on Peter the girl is there again, walking the opposite way on the other side of the huge sidewalk. You see her about 5 times going back and forth to the building. The first few times she's alone, then she's walking with another girl. (00:05:55)
Continuity mistake: Near the beginning of the film when we see Peter waking up and reaching for his glasses, in the previous shot he didn't have the blanket on him or over his shoulders, it's in the background on the floor, yet when he reaches for his glasses the blanket is on his shoulders. (00:17:05)
Continuity mistake: In the scene in which Peter and Flash are fighting in the hall, Harry runs up to Mary Jane to see what is happening, seconds later Peter jumps up to avoid Flash's friend charging him from behind. In the shot of Peter flipping in the air, you can see that Harry is no longer standing next to Mary Jane, a girl in a blue sweater is. After Peter lands, the camera cuts back to Mary Jane and Harry is once again by her side. (00:24:25)
Continuity mistake: When Spider-Man catches Mary Jane as she falls off the balcony, in the shot from above there are two columns lying on the ground - one on the right as we look at it, a few feet from the red area and parallel to it, and one on the left at an angle. In the shot of them landing, the one closest to the red area has disappeared. (01:06:50)
Continuity mistake: At the World Unity Festival, Peter is taking pictures. When he looks up at Harry and M.J. on the balcony, his camera, which has been your average "right handed" camera throughout the film, magically becomes a "left handed" camera. The shot's obviously been reversed - his parting's on the wrong side as well. (01:02:10)
Other mistake: In the scene after Spider-Man stops the convenience store robbers, it shows a newspaper article. This article virtually repeats itself. Here's what you can read: "Witnesses claim an unknown masked man was seen exiting the Ling Deli after stopping two suspects from attempting to rob the establishment. Police spokesman John Young said "we've heard of Samaritans, but in 20 years I've never seen anything like this." The two suspects were taken to the county jail....(cutoff)....attempting to rob that same establishment. Police spokesman John Young said "we've heard of Samaritans, but in 20 years I've never seen anything like this." The two suspects were taken to the county jail." (00:52:25)
Continuity mistake: When the part of the balcony where Mary-Jane is starts to break, there's a lamp on it. It vanishes the following shot, then reappears some shots later. (01:07:05)
Continuity mistake: When Osbourne is talking to Peter at the graduation, the scene keeps changing from him having one hand on Peter's shoulder to both to none. You see this just after Harry sees Mary Jane break up with Flash. (00:49:40)
Continuity mistake: When Peter is practising throwing spider webs in his bedroom, his first attempt hits a model rocket and it breaks in many pieces. A few shots later when he finally hits the Dr. Pepper can, as he whips it across the room you can see the rocket back in one piece, just leaning against the wall. (00:33:15)
Visible crew/equipment: When the fire breaks out in the building, as the firetruck goes by you can see the reflection of the camera crew on the truck, including a man wearing a white shirt. (01:22:00)
Continuity mistake: At the start of the Unity Festival scene just after we see Peter taking a picture, it cuts to Macy Gray, in the first shot she is not holding onto the mic stand, yet in the following shot she is. (01:02:00)
Continuity mistake: In the film Norman Osborn is talking to the board of the company where they announce they are selling the company. In one shot if you look on the table most of the folders that the board are holding are open. In the following shot most of them are closed. (01:00:30)
Continuity mistake: When Spider-Man is fighting the thugs that attacked Mary Jane, at one point he lifts a thug in the air and they are in the middle of the street. After it cuts to Mary Jane, now Spider-Man is holding the thug in the air with one foot on the curb. (01:17:05)
Answer: Remember that Green Goblin (Norman Osborne) just found out that Peter Parker is Spider-Man. Aunt May's comment about everyone knows he loves Mary-Jane concerns him because he now realizes that Green Goblin might find/kidnap Mary-Jane just to lure Spider-Man into a fight. This is the basis for the whole reason he can't be with her, as he would be potentially putting her in harm's way all the time if they got together.
Jazetopher