Revealing mistake: When Nica crawls to the elevator to escape Chucky, she bends her legs in order to shut the elevator door. She is meant to be a paraplegic and have no feeling in her legs.
Revealing mistake: When Nica goes to investigate the screams in the first part of the movie, as she opens and closes the door she appears to be moving in a way that implies she is standing and not sitting in her wheelchair, this completely contradicts her being a paraplegic.
Revealing mistake: When the pastor is beheaded you can see a clear tube inside his neck that is squirting blood.
Suggested correction: That's actually supposed to be the top of his spinal cord. The blood is noticeably coming from behind it if you look closely.
Revealing mistake: When we see Jill's webcam image on the remote laptop during the electrocution scene it is from Chucky's point of view, and not her laptop's webcam.
Revealing mistake: When Chucky is trying to kill Nica with the fumes of the car, you can hear him hit the gas and the engine revs, but the smoke from the silencer has a constant flow.
Revealing mistake: When Ian's jaw gets hacked off, the blood that splatters on his shirt almost all just beads and rolls off, rather than sticking, and is super thick, revealing it's fake.
Revealing mistake: When Officer Stanton has Father Frank's blood splash on his face, pay close attention to the second shot of him staring with his mouth open. Some of the blood on the right side of his face appears and disappears a few times in the second shot, revealing it was added digitally and there was a flub in the rendering.