Deliberate mistake: It's a humorous twist that Randy's killing is covered up by some random guys passing by with a ghetto blaster, but there was dead silence when Randy was talking earlier; not being in frame does not block soundwaves. (01:05:15)
Deliberate mistake: Several times, you see an exterior shot of Nathan's house, and it is very clear that it is the same shot being used over and over, sometimes reversed.
Deliberate mistake: While walking bare-footed in the barn looking for RJ, Wayne does not raise his feet very high - that is, until he is about to tramp on the nail that is perpendicular to the floor. If Wayne had kept walking like he had been, he might have bumped into the nail or object holding it up, but not got punctured by the nail. (01:06:40)
Deliberate mistake: When Ben is discussing boarding up the windows to Tom, he says he still needs to get a few spots upstairs. Why would he need to board up the upstairs windows when the zombies have no way of reaching them?
Deliberate mistake: After Venom eats the head of one of the Drake's henchmen there is no blood from the wound.
Deliberate mistake: When they are listening to the tape, Cheryl yells out and shuts it off. Scott says he wants to hear the rest of it, but then deliberately fast-forwards it a bit before starting it playing. If he wanted to hear the rest of it, why does he skip part of it? This allowed Cheryl to shut it off as soon as she finished her line/action, but then Scott could fast-forward it past a mark on the visible reel-to-reel tape so it would start immediately on the chanting rather than in the middle of the lecture where Cheryl stopped it.
Deliberate mistake: When Margo is in the Superstition exhibit, she thinks she hears/sees something and runs for her life. She gets into the women's bathroom and tries catching her breath before the mirror. Hearing a noise outside of the bathroom, she goes into a stall, locks the door, and stands up on the toilet so her feet don't touch the floor. It was just a little old maid washing her hands outside the stall, and the strange sound Margo heard was the maid using her inhaler. However, how is this little old lady - with asthma, we can assume - supposed to have gotten all the way from deep inside the exhibit to the women's room within seconds, pushing a big heavy cart? Why would she even be in such a hurry? We can assume, however, that perhaps this was a deliberate mistake to show that, after all, maybe Margo wasn't just freaking out over nothing...that perhaps something was in the exhibit with her.
Deliberate mistake: The blades on the tiller or harrow (?) were only a few inches apart when Burkett was falling back onto them, but only one blade went through his chest. Burkett's body was wide enough for at least three blades to penetrate. Also, the blade appeared to be exiting in the center of his chest (along the button line of his shirt), but the close-up showed the blade to his right. (00:19:40)
Deliberate mistake: Candy tells her radio listeners, "Our phone number is 201-5137." Assuming the radio station's reception extends beyond more than a small geographic area, an area code is needed for callers outside of the immediate area. On Ellie's cell phone, Mary's number shows up with an area code. (00:05:55 - 00:07:20)
Deliberate mistake: The disco ball doesn't start reflecting the sunrise until after the lead characters get out, even though it should have began to reflect light right when the door opened.
Deliberate mistake: In the whole of the 'Psycho' series, there has never been a closet door next to the dress cabinet in Mother's room, but for this movie there is suddenly a closet.
Deliberate mistake: When they're watching the footage of the tsunami hitting Cannon Beach, Sabrina turns the TV off as the shot pulls backwards. Suddenly, the glare on the TV appears out of nowhere.
Deliberate mistake: When the scanners escape the apartment in the van and the assassins are in pursuit there is a street view shot of the assassins driving up next to the scanners' van. If you watch the street on the right side of the screen you can see people stood watching the filming in groups, out of harms way. (00:50:28)
Deliberate mistake: The legion of hellspawns during the film's climax are merely copied and pasted throughout the screen, as evidenced by the fact that many of them perform the exact same distinguishable body movements, such as pacing right and left from a crouched position.
Deliberate mistake: Frequently during the movie, British surgeons are referred to as "Doctor". In Britain, surgeons are always referred to as "Mister"; this is a hold-over from the surgeon's non-medical past (barbers, etc). This would likely be confusing to American audiences.
Deliberate mistake: When Tiffany is reading the self-help book for recovering addicts, there's a closeup of a page. While the headline for the chapter makes sense, the body text is completely unrelated and is about corporate work culture. (Likely just some generic free text the prop department copy/pasted into the book prop.)
Deliberate mistake: After the AN-12 launches from the carrier, you see U.S. Navy near the nose of the craft, and MG on the tail code (MG=McGuire Air Force Base). Also, during the flight shots, the plane transforms between a C-130 and AN-12 multiple times.
Deliberate mistake: There is one vertical board missing between the other parallel boards, but the upper half of the gap is wider and forms a "V" when Mark is videotaping Jenna (who is on the other side of the fence). The missing board, between two parallel boards, has a uniform width from top to bottom. (00:08:40)
Deliberate mistake: The images of Spencer's face in the driver's side mirror are not realistic for someone in the driver's seat. The driver's side mirror is angled outward (perhaps 60° beyond a typical angle), but his face is perfectly reflected. When Spencer starts smoking, the viewer gets a glimpse of a figure behind his car. Spencer senses something and his face is shown backwards in the mirror, as if he were crouching outside a few feet from his car. Spencer does not use the more practical rearview mirror. (00:19:11 - 00:19:47)
Deliberate mistake: The doctor appears to write just three numbers or a short wavy line on the back of his business card for the phone number he told Marjorie to call (to get a second opinion about Nathan). (00:42:35)