Continuity mistake: When Kristen meets the little girl drawing the chalk house, between the two shots before it starts raining, the chalk drawing changes. (00:02:35)
Continuity mistake: When Kincaid's dog runs under the bed, it kicks a carpet away from the bed. Beside the bedpost there is a white sock. When it cuts, the sock has moved onto the carpet. (00:05:15)
Continuity mistake: When Kincaid falls backward out of the chair we see his dog sticking its head out under the bed. When it cuts to Kincaid falling through the wall, the dog isn't under the bed. (00:05:20)
Continuity mistake: In her dream, Kristen is bitten by Kincaid's dog on her left arm. When she wakes up, the wound is on her right arm. (00:06:25)
Continuity mistake: When Kincaid's dog is getting ready to pee it has its tail between its legs. When it cuts to the fake dog peeing flames, the tail is standing up. (00:15:40)
Visible crew/equipment: When Dan pulls up in his red truck, before he goes into the restaurant, you can see the crew reflected in the side of the truck. (00:26:45)
Continuity mistake: After Kristen first falls into the quicksand, the shot changes, and a palm tree appears which wasn't there before. (00:34:35)
Continuity mistake: When Kristen falls into the quicksand, there's a shot of her from behind, and her back is covered in quicksand, although her back hasn't been in the sand yet. (00:34:35)
Continuity mistake: When Freddy push Kristen into the quicksand you see only her hand sticking up. Then in the next shot suddenly you see her hair. (00:35:00)
Continuity mistake: The hole in the roof which Kristen makes when she falls through the roof changes size between the shots. (00:35:05)
Continuity mistake: When the nib of Shelia's pen starts bleeding on her test, the pool of blood on her paper moves between shots. (00:42:30)
Continuity mistake: When Sheila's pen starts to bleed, she puts it down on her desk, with the lid off. In the next shot there's a lid on it, and the pen has also changed it position. Her inhaler has also changed position. (00:42:40)
Continuity mistake: When Sheila's pen bleeds, she puts the pen down, then smears the blood around her physics test. Between shots, the way the blood has smeared changes. (00:42:45)
Continuity mistake: When Freddy is reaching out to take Sheila's glasses off, you can see that the palm and index finger of his hand aren't scarred at all from what was supposed to be an all-consuming fire. (00:43:55)
Visible crew/equipment: After Freddy 'sucks' Sheila, Freddy says "You flunked", then it cuts to Alice trying to get out from her desk. Under her desk you can see someones fingers briefly. (00:44:25)
Revealing mistake: When Shelia is dying, Alice is trying to help her, but she is 'thrown' to the floor. Then there is another shot of Shelia, and you clearly see a pulse in her neck, although she's meant to be dead. (00:44:50)
Continuity mistake: When Dan is talking to Alice there is a piece of paper in front of him on the table. In the next shot it's gone. (00:47:40)
Revealing mistake: During Rick's nightmare, we can see the fake reflection trick in action when Kristen is taunting him in the mirror. When she turns around, the actor playing her reflection turns out of sync, and brings the wrong hand up to her mouth. (00:53:13)
Continuity mistake: At Rick's funeral, Debbie gives Alice her spike bracelet. The spikes are flat and there aren't that many of them, but at the end when Alice is getting decked out to fight Freddy she pulls the bracelet out of her drawer, and the spikes are very menacing looking and there are more of them. (00:55:25 - 01:13:20)
Revealing mistake: After her brother's death, there is a scene in which Alice starts practicing with her brother's nun-chuks. They never show the real actress doing the tricks; instead, they cut to an angle from behind her and show a double who has darker, shorter hair than the real actress and is a bit bigger. (00:56:45)
Answer: As Kristin was being burned to death in the boiler, she passed her ability to pull other people into her dreams to Alice. This enabled Freddy to get new victims.