Other mistake: When the bear falls on Eddie, they are facing the same direction, but Eddie says that he knows the bear is a girl "Because its vagina is on my ear."
Other mistake: When Anika falls to her death, as she lands, there's already a moderately-sized puddle of blood beneath her, which makes no sense, as she only just landed that instant. Then, when it cuts immediately to a wider shot about two seconds later, there is suddenly even more blood around her body.
Other mistake: At first, Ethan tries to board the train by waiting until it slows for a sharp bend. Thanks to The Entity, the train is going pretty much full speed throughout, but doesn't derail or tip at the lower speed sections. In fact, the diners are all blissfully unaware that this is, in effect, a runaway train as they consume their canapés and fois gras, with soft music playing in the background.
Other mistake: After the first guard at the chemical plant is sniped, the second guard goes to check on him and is surprised by the sudden appearance of an attacking helicopter. Helicopters are extremely loud, and flying as low as it was depicted would also vibrate the ground and the building. There's no way it would have been able to sneak up on the guard like that.
Other mistake: The window looks closed, but even if the window is open, the woman ironing in her house across the parking lot would not be able to hear Jay and Maggie's argument from that distance, only muffled voices at best. (00:05:18 - 00:06:11)
Other mistake: The sun is shining and the road isn't wet, but a shot of the windshield when Paul turns his head toward the backseat shows short diagonal lines covering the windshield. The image suggests but does not resemble rainfall. In front views, the windshield is clear. (00:09:48)
Other mistake: All the websites, both in the address bar and the results of the search, have no top-level domain like .com or .org. Everything is just www.something instead of www.something.com. (00:10:30)
Other mistake: Halfway through the film, a cityscape with the subtitle "Russia" is shown - the city is, in fact, Atlanta. Skyscrapers such as the SunTree Plaza, Westin Peachtree Plaza, and the Georgia-Pacific Tower are visible. (01:24:00)
Other mistake: Just when the tower clears 119 to take off, it shows the PFD and MFD screens. On PFD it shows air speed 250 knots and altitude 40000 feet which could only be happened when cruising in air. Also, on MFD it shows ground speed 250, and no flight path displayed. (00:09:00)
Other mistake: When Father Amorth takes the key from the caged corpse's stomach, it's obvious that nobody could have swallowed it in the first place.