Continuity mistake: While father and son are eating beignets, the passers-by behind them are not continuous between shots.
Factual error: The alien drops the video camera out of the UFO from outer space and it falls to earth landing on the ground. This very far drop would certainly have busted it to pieces, if not ignited it on reentry, but when the guy picks it up off the ground, it appears only the screen is cracked.
Continuity mistake: When Elizabeth Banks is getting out of Amos' car, when they get back from Bible study, from Banks' angle, you can see that his hand is on the knob on the steering wheel, whereas when the camera changes to Amos' angle, he isn't touching the knob. When the camera changes back to Banks, you can see his hand back on the knob. (00:48:10)
Continuity mistake: The dog the boys were trying to catch was facing the fence with his nose very close to it. After one of the boys threw a blanket (or piece of material) over the dog, the dog was facing them instead of the fence. Also, the dog was not as close to the fence and the background didn't appear to be the same. (00:06:07)
Continuity mistake: At the end of the film we see stuff being crossed out in a notebook. The lines that are drawn through the words keep changing from being perfectly straight to being at an angle.
Continuity mistake: As the jeep with the killer goes over the cliff and smashes face down you can see nobody is in the jeep as it disintegrates the front part. (01:14:00)
Factual error: When the guy is talking to him on the phone and the Russian smashes it on the floor, the phone smashes and the battery comes out but the guy other end can still hear him. (01:04:00)
Continuity mistake: As the two assistant workers walk away from the prison building at the end of the first day, Charlotte Gainsbourg's grip on her folders switches between shots.
Continuity mistake: When the guy is protecting his home and clearing the window with his shotgun you can see him breaking the glass on the bottom left window pane. In next shot it has the piece there again. (01:43:55)
Continuity mistake: When Dex sees "his" son for the first time, the kid in close-ups is playing with the toy that dangles from above, and there's a toy football by him. In the wider angles none of the above is happening. (00:38:40)
Factual error: When Felix reveals Roxy/Stacy's IP to the world, it is 195.243.245. That is not a valid IP, it is missing the fourth octet. (00:14:00)
Revealing mistake: At the end the sides of the grave (which Jack just had dug by spade) are too perfect. Only an excavator could get such neat sides.
Continuity mistake: When the kids are looking at the Stonehenge-type structures, the younger boy calls for everybody to come and see the hidden message. From the shot in front of the boy you can tell from his body position he's sitting up, however in the next shot from overhead, the boy is now lying down on the rock.
Factual error: Narration refers to Hitler's Germany research into nuclear fusion - it was nuclear fission they were looking into, the same as what fueled the WWII-ending bombs in Japan, and every nuclear bomb and missile since. No nation has been able to generate nuclear fusion until very recently, and it doesn't produce an explosion - which is what Hitler wanted. (00:08:35)
Revealing mistake: Tortured by the demonic voices in his head, Michael King goes into a self-mutilating frenzy with a kitchen knife, except that he squeezes the handle of the bleeding-knife prop a bit too hard and it squirts fake blood horizontally across his chest.
Continuity mistake: When we first see the male volcano, he is an entire island with trees and forests. After many years have passed and sinks into the ocean, it can be seen the trees and forests have now gone. However, after he spews out of the ocean and is together with the female volcano, the male volcano suddenly has trees and forests around him again.
Factual error: When the high-ups at the Pentagon are looking at the profiles of the terrorists, Ulrika's profile contains a minor spelling mistake ("Americas" instead of the possessive form), but the fun is in her henchman's file. The guy is named "Grigori Babishkova", which is laughable since "-ova" is the female suffix for Slavic last names, he should be "Babishkov." The Nationality field lists him as being "Russian/Caucasian." Caucasian is not a 'nationality'. (00:05:05)
Revealing mistake: Late on in the film; Arnie and the female officer kick in the door to one of his teams house. Unfortunately Arnie is in his 70s now and not as agile as he used to be, the door was open and simply pushed hard. Look at the door, it has no damage and neither does the frame. Also, the door barely opens past a hard push. As tactically trained operatives they would not have pushed the door if it was ajar either, they would have opened it slowly to avoid startling anyone inside and warning them.
Continuity mistake: During the scene of the first meeting between Gus and Ruby, Krysten Ritter's hair moves back and forth (behind or in front of her left shoulder) between shots multiple times (most obvious example: when he offers her a drink). (00:12:45 - 00:14:35)
Revealing mistake: About seven minutes in, during the scene where we see Cooper helping the Nerd as a cameraman, you can tell that Cooper has been added to the scene using green-screen effects, as the actor was unavailable to shoot at the location. The lighting on Cooper doesn't quite match the lighting of the scene, and you can see a slight "blur/feathering effect" around him where the greenscreen background was removed.