Plot hole: In the end, when Charlie is advancing on Emily while turning his light on and off, the final time he turns it on, Kathrine is in front of Emily. How could she get there so fast without being heard? There's at least 4-5 inches of water that would make sneaking very hard.
Add timeJames King III
Continuity mistake: When David (in fact, he was Charlie that time) was looking for Emily in her room, he checked if she was under either of the two beds. After he bent down, he was checking the bed on his right side, but when he was shown from another camera angle, he was checking the bed on his left side, before he lifted his head again.