Corrected entry: The whole film doesn't work - no-one in the film could possibly be the killer. At the times of the murders all the cast are accounted for.
Corrected entry: In the film the four friends figured out who the killer was because of his link to the mask that Kate found in her elevator. I wonder how they came to this conclusion as at the beginning of the film it is not Jeremy Melton who is wearing the mask, it is a child watching him.
Correction: They didn't decide Jeremy was the killer because of the mask. They thought of him because of the initials JM, seen on the Valentines they received, and because Dorothy realised she'd given him a pretty strong motive. The mask was merely something to confirm that Jeremy Melton could be involved, as it was a pretty big coincidence.
Corrected entry: When Lily is shot with all of the arrows and falls into the dumpster, why doesn't anybody discover her body throughout the rest of the film? Wouldn't somebody notice her body when emptying or adding garbage to the dumpster? The dumpster was full of garbage, meaning that it is frequently used.
Correction: Lily was killed one day before Valentine's Day, so it's only really been one day that the garbage has been there and it wasn't filled to the top either.
Corrected entry: In the beginning, Katherine Heigl is working on a cadaver and has surgical gloves on. When she thinks someone is after her, in the close up of her squeezing the surgical knife, the gloves are gone.
Correction: When she has both gloves on and hears something, she takes both gloves off. When she returns to the cadaver, she only puts one glove back on and it remains that way until end of the scene.
I agree, there is no mistake in the scene. Either the person didn't recognize the glove was on or missed her switching the scalpel to the non-gloved hand. Incidentally, this mistake is listed on IMDB and was possibly copied from there without verifying the scene.
Corrected entry: At the end of the move when Kate is running around the mansion, where did all the party staff go? Would someone as wealthy as the family is supposed to be just leave their house trashed like that?
Correction: All the power was out remember it would be pretty hard to clean up in the dark they may have said they would come back in the morning when there was light to pick up or even by law forced to stop working since there was no light as it can be a unsafe enviroment.
Corrected entry: Why is Lily watching dating tapes when she has a boyfriend? And also if you looked like that, then you wouldn't need to watch dating tapes, men would be falling all over you already.
Correction: It's Paige watching the tapes, Lily is just there with her. Also, on the comment that you can get a man just by being beautiful, there is an amazing amount of things wrong with this, as it could be down to a lack of confidence, not meeting the right people, wanting someone who hasn't met her who doesn't like her for looks, there are many single beautiful people in real life.
Corrected entry: In the scene where Lily is being shot with arrows when the killer is firing the first two arrows his nose is already bleeding. However, when he fires the third arrow his mask is clean, his nose is not bleeding and his nose only starts to bleed again when he pulls back the string on the bow.
Correction: Actually, the killer's nose isn't bleeding, it's just a shadow from the bow and arrow.
Corrected entry: In the scene where the killer is after Shelly she stabs him with the scalpel she was using then drops it. As she is running and presses the lift button there is no scalpel in her hand but when she resumes running away the scalpel is back in her hand.
Correction: Actually the scalpel is in her hand, although not very visible. In some frames you can see only its shadow on the wall.
Correction: It is pretty obvious that Adam is the killer and he is not accounted for at the time of the murders.