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)Casual Person
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.Charles Austin Miller
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.
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.GeordieB