Revealing mistake: At the end when April and Kyle are killed, they are thrown in a hole back first. When they are shown, they are neatly positioned beside each other. April even has her knees bent up and Kyle has his arm around her waist meaning they obviously positioned themselves for the final shot.
Revealing mistake: When we see the funeral, the coffin is lying on wooden planks across the grave as it should be. However, the green sheet is perfectly flat, but not stretched, showing there is no hole under the coffin. (00:45:00)
Revealing mistake: In the Kentucky church-massacre scene, Harry briefly scuffles with a man in a light blue sweater. Harry elbows him in the ribs, sticks a grenade in the man's pocket, spins him around and delivers a crushing blow to his neck, then hurls him head-first into a wall. Throughout this sequence, the man is obviously a live human being. However, a fraction of a second before he impacts the wall, he transforms into a life-size rubber dummy before our eyes, in mid-frame, without any obvious camera cut. This demonstrates the complexity of the scene - it is a digitally-edited collage of action sequences almost seamlessly strung together into what appears to be one long traveling shot.
Revealing mistake: When Four injects Tris with the serum before taking the test for the first time, it is very apparent the syringe is not injected into Tris' neck. The tip of the syringe is merely just touching the skin of Tris' neck and the syringe is shown moving around her neck. (01:07:30)
Revealing mistake: When the girl gets her head cut off with the barbed wire, when her body falls to the ground, her feet bounce around like rubber.
Revealing mistake: At the end of the movie, it's pouring rain but the 2 survivors aren't getting wet at all.
Revealing mistake: When Thomas is running through the blades to rejoin the other runner, as they run into each other it is a CGI background. (01:08:50)
Revealing mistake: In the scene were Viago is showing the locket that his girlfriend, Katherine, gave him, he puts it on, and since it's silver, it starts to burn his skin. The smoke from his burning flesh is coming from something on the table in front of him, not from inside his shirt.
Revealing mistake: When Millie is being carried away, her head remains completely upright as though under her own control. If she was dead her head would hang back.
Revealing mistake: Most of the tank battle scenes throughout the movie are low budget CGI.
Revealing mistake: In the POV shot from Thomas, capturing Bill and Ben puffing away from the water tower, Thomas seems to be off-centered from the tracks, making it seem like he is derailed.
Revealing mistake: Tommy picks up a chair and breaks it on a desk, but the chair breaks just before contact. (01:25:30)
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.
Revealing mistake: During the battle of Dale, Bard confronts Alfrid, who is dressed as a woman and is trying to escape with looted gold. During the confrontation a troll climbs over the parapet and is killed by Bard. As the troll falls, Alfrid also falls. When he lands, the ground near his hand ripples like fabric covered in sand.
Revealing mistake: Jim parts his hair on the left side. The stacks of his books on display in the hallway include a photo of him with his hair parted on the right side, but otherwise looking the same. Hair that is persistently parted on one side will not easily part on the other side and lay across the head in the same way. (The image was reversed). (00:25:20)
Revealing mistake: Tanner Boatwright was used as a leg double for Augustus. In the part of the sex scene where they shoot from the feet up, you can see that the amputated thigh is thinner and has a slightly different colored tone of leg hair than Ansel's actual leg. (01:05:25)
Revealing mistake: When Felix talks breaking the fourth wall about the mysterious, vicious "Roxy", he shows her twitter page. The latest tweet is dated Mar 10. Since the school at that moment still has to issue the report cards for the first semester, it seems a little too far ahead in time. (00:08:40)
Revealing mistake: The luminaries lining both sides of the driveway were not lit, although there were a few bags that contained a small circle of dim light that gave the impression of being lit. One of the bags was nonetheless able to catch Boyd's pants leg on fire. (00:11:42)
Revealing mistake: JR is in the weapon container of the crazy dealer, who passes him some of his goods. JR ends up holding in his right arm a MP5K and an M4A1, which combined are about 5 kilos, but then he passes him an M60 Machine Gun, which weighs over 10 kilos and that the relatively diminutive protagonist just handles throughout the scene gripping it with his left hand and making no effort whatsoever. (00:25:20)
Revealing mistake: As Glenn, Blake and Monica are being surrounded by zombies, as Monica asks "Fucking hell, how many more of these are there?", in the background you can see a zombie sitting astride his victim, flailing away with a hammer or hatchet. It is obvious that he is just swinging his arm back and forth, without connecting with anything. It looks as if he is dusting, not slaying someone. (01:23:50)