Continuity mistake: Ben pulls Madison into the pool and her hair is straight. When she's dead, her curls magically appear. (01:18:30 - 01:20:00)
Continuity mistake: When swimfan85 is trying to talk to Ben and he tells her he has homework to get done, she is talking with the nick name swimfan85 but when she signs off it says "swimfan has signed off." They forgot to add the 85.
Continuity mistake: When the main character is swimming and then bumps into Josh who is dead, in the shot underwater there is a lot of blood, but when it cuts to above the water, there is no blood in the water, and when it cuts back to below the water, there is a lot of blood again.
Continuity mistake: When Madison seduces the guy in the pool, she enters the pool but never puts her head under the water. But in the close up of the two making out, all of her hair is soaked as if she dunked her head.
Continuity mistake: When Ben is talking to swimfan online, in the shot facing him he is typing quickly and smoothly. When it cuts to the computer, he is typing slowly.
Continuity mistake: In one of the scenes where the main actor is driving his truck, there is a broken orange light on the roof. When the truck is shown a few scenes later the light is fixed.
Continuity mistake: After Ben nearly hits Madison, he gives her a ride home and she leaves her music notebook in his truck. When Ben is sitting in his room mulling over returning the book to her, the diminished amount of daylight coming into his room suggests that it is early evening approaching sunset. Yet, when he goes to her house to give her the notebook, the sun is shining brightly as if it were still afternoon.
Continuity mistake: In various scenes, you see inspection stickers on the windshield of the main guy's truck, then they disappear.
Continuity mistake: When Ben and his girlfriend are in the diner where she works, they're talking at the bar (the scene right before the one with Madison and Josh making out in the car), and Ben's girlfriend tells him that she thinks he should leave. In her close-up her head is resting on her arms, which are crossed. Next shot, when Ben is walking toward the exit, she's sitting up straight. Then in her next close-up, her head is once again on her crossed arms.
Continuity mistake: When Madison pushes Amy into the pool while handcuffed to a chair, the camera shows a close up of her handcuffs behind her back at the bottom of the pool. Amy's handcuffs were applied with the swinging jaws inward, towards her back. In a subsequent shot, Ben is picking the handcuffs to free her and the swinging jaws are facing outward.
Continuity mistake: When Ben and Josh are talking in the locker room for swimming, Ben has all of his clothes on. We see Josh for a second and then go back to Ben who is now in his bathing suit.
Continuity mistake: When Ben and Madison are in the pool together for the first time, the camera is behind Madison. You can see that Ben's hair is completely wet and slicked down. When the camera is behind his back, his hair looks more dry and a little is sticking up on top.
Continuity mistake: In the scene at the party, when Ben is introduced to Madison, and then she meets him outside the bathroom, she pulls her cardigan down off one shoulder. In the next shot it is off both shoulders and in the shot after that it is only off one shoulder again.
Continuity mistake: When they are at the party, Ben first walks in, takes off his jacket and drops it in a chair, then he proceeds to hug Amy and gets introduced to Madison. In one shot his jacket is off, in the next it's on, then it's off again.
Continuity mistake: When Ben drops off Madison at her house, from the passenger side, you can see he has his seat belt on. When he drives away its off.
Continuity mistake: When Ben is teaching Madison how to swim, the depth of the pool goes from 9ft to 8ft when they move in deeper.