Revealing mistake: In one shot when Alice is in the shower, as she turns for the soap you can tell she is wearing brown underwear. (00:03:30)
Continuity mistake: When Alice and Mark are collecting all the sheets from the floor, Alice looks at a sheet about Amanda Krueger. Then in the next wide shot as her dad calls for her, all the sheets are in a pile to her right. Then in the following closeup, she starts picking up sheets of paper from all around her. (00:53:35)
Revealing mistake: When Alice picks up the photocopied sheet about Amanda Kruger, if you pause, and read the article, it is actually about tax and the government. (00:53:30)
Continuity mistake: In the beginning when they are at graduation, Alice is walking with a piece of paper and ribbons attached. In the next shot the paper is not in her hands and her boyfriend surprises her with the same paper with the ribbons. The paper was tickets. (00:09:30)
Continuity mistake: When Dan and Alice are making out you see his empty hand on her head. Then suddenly he has his graduation diploma in his hand. (00:12:15)
Audio problem: From a side view, when Alice yells "Come on Jacob, it's time to go home" her jaw moves to other words. (01:13:10)
Continuity mistake: Right at the start of Chapter 15 on DVD:- Alice is holding a sheet "A victim of the evil within us all." Then she hands the sheet over to Mark. Then in the next shot as Mark holds the sheet Alice just handed him, you can see through it, and the title/layout of the sheet is completely different. (00:56:00)
Continuity mistake: When Alice and Mark are discussing Amanda Krueger you see Jock has a pencil behind his ear. In the next shot it is suddenly gone. (00:56:25)
Revealing mistake: When Jacob says to Freddy "I wanna learn stuff from you, she's no fun anymore" Freddy then raises his metal claw to his nose. His nose then hits the claw, and it bends. (01:17:05)
Revealing mistake: The fake hand that the wires snake into was shot backwards and reversed, so you can see the holes where the wires are going to enter. (00:26:55)
Revealing mistake: When Alice has a sudden vision of Dan falling to hell (or wherever) behind her, the perspective she has is impossible. The fall-away shot starts from an extreme close-up of Dan such that his head alone is twice the size of Alice, making it obvious that this is nothing but a filmed visual inserted into the background. (00:29:24)
Continuity mistake: When Greta is being stuffed with food, Alice opens the refrigerator to get food, which spoils. As the camera shot goes from close to further away, there is suddenly more food in the refrigerator than there was in the close up shot.
Answer: Her death was from Freddy overfeeding her while in the real world she choked to death.