Corrected entry: When the killer calls Helen from the club and plays the tape from the lecture, there is no music in the background when heard from Helen's end. But the music at the club is so loud, it would have been heard.
Corrected entry: When Helen Hudson is emailing Peter Kurten, how did she get his e-mail address when she and Inspector Monahan couldn't even find out who sent the warning before the hippie girl's murder?
Correction: She doesn't - if you watch, she sends a message out to everyone on her circle of online chat friends. Since the copy-cat has already infiltrated it somehow, he should (and does) get the message that way.
Corrected entry: Segourney Weaver is attacked in the bathroom at the beginning of the film. The attacker is already in the bathroom waiting for her. How could he know she was going to need to use the restroom? His whole plan of attack hinges on her going into the bathroom. Her going in there could only be to further the plot of the film.
Correction: Not exactly a plot hole. If he had say picked somewhere that she would never go into or would have no reason to, then yes it would leave a serious question as to how he knew to set up there. As for his plan, it might have been through experience, research etc. that he chose to set up in the bathroom. She had just given a lecture and the average person after something like that will likely need to use the toilet. Simply put, he was correct and she did come into the bathroom.
Corrected entry: Reuben calls Helen after the "Berkowitz" style murder and tells her that they found a note in the payphone. He even reads her part of it. But later when Rueben and MJ are at Helen's apartment, Helen asks about a note, and if she was right about its location, as if she hadn't been told already.
Correction: She could have forgotten, in her fright over the recent attack on her. Or it could have been a rhetorical question to demonstrate how crazy the culprit is.
Corrected entry: Isn't it strange that the cops never thought to look in the local sperm donor banks for their killer? They were totally baffled as to where he got two samples.
Correction: This is a typical character error. Fertility clinics would be the best place to start, but they most likely did not think that it would be so simple, seeing how much trouble Kurten went through to copy other people's crimes in minute detail.
Corrected entry: At the start of the film when Sigourney tells all the white males in the audience to stand up, there is a fairly confused looking oriental guy in the middle of the frame standing up.
Correction: Character mistake, if anything. Like you say, he is fairly confused. Maybe he was not paying too much attention, or maybe he is half Caucasian and therefore not sure whether to stand up or not.
Corrected entry: Near the end in the toilet scene, Holly Hunter's white blouse is splattered with blood. A few moments later on the roof the blouse is brilliantly white.
Correction: The part that has blood on it is covered by her jacket. All you see on the roof is the collar.
Corrected entry: When Hudson realizes someone is in her house she grabs a knife out of the wooden knife holder. It makes the hollywood "shing" sound but how could this be if it came out of a wooden holder not a metal one?
Correction: Once I read this comment, I decided to see if the knife in the wooden holder would make the "shing" sound. I have the wooden knife holder and it DOES make the shing sound if you pull it out quickly like she did.
Corrected entry: In one of the last scenes at the bathroom where M.J. Monahan is being shot by Peter Foley, she is wearing a bulletproof west, the mirror behind her still breaks. It can't be due to the sound, because they're not all breaking.
Correction: She is shot once in the bullet proof vest, and once in the shoulder, which goes through and shatters the mirror.
Corrected entry: The killer is trying to replicate Harry Connick Jnr's attack on Sigourney near the end of the film, but he forgot about the two pieces of toilet paper she put on the seat. It seems strange that someone who is such a stickler for detail would leave something like that out, especially since the filmmakers made such a big deal out of it originally (there were detailed close ups of the paper being put on the seat).
Correction: I believe the camera was just following Hudson going through the motions of using the bathroom and also following Connick's motions of preparing for his kill. If you notice how Hudson was kicking when she was being lifted up I'm sure the toilet paper fell to the floor, therefore Connick, the second killer or anyone else who may have taken pictures of the scene would not have even noticed it as a big deal.
Corrected entry: Isn't it strange that Sigourney's character is meant to be agoraphobic (afraid of large spaces), but she lives in an apartment bigger than your average football field. It's only when she ventures into the (much smaller) corridor that she has a fit.
Correction: Agoraphobia developes when a person avoids spaces or situations associated with anxiety, the anxiety of course being the situation that happened in the bathroom. So any place outside her house became unsafe to her, reguardless of its size.
Corrected entry: In the beginning when Helen asked the boys to stand up, you can see Peter Kurten standing in the front row.
Correction: This isn't trivia - it's a key plot point the murderer attended one of the doctors lectures and was copying them in the order she mentioned them.
Corrected entry: The serial killer is copying the style of murder of some of the most ruthless serial killers ever. He copies Jeffrey Dahmer's by drugging a gay guy at a bar, puts a bag over the guy's head until he suffocates, then saws off the head and disposes of the body in a river. This is not how Dahmer did it! Dahmer did not suffocate them and he did the killings at his home, not an alley. He also cannibalised the bodies and kept the skull in his fridge.
Correction: Dahmer killed 17 men, he didn't cannibalise them all, he started killing before he had his own home, so really he could have killed one in this way.
Correction: The music from the bar was heard from Helen's end.