Revealing mistake: During the final battle in hell, when the army of Spawns rise up, there are some small errors to look for. First, during a few shots where the army is closer to camera, you can see the CGI army becoming "pixely." Also, you can see at least one of the Spawn floating in the air, not standing on the platform with the rest of him. Problems with the CGI rendering/animation.
Revealing mistake: In the scene, when the bug (actually another Kothoga monster) run out from the box that Margo has opened due to strange noises, there are visible wheels from the puppet of the bug. (00:48:40)
Revealing mistake: In the locker of the Gentleman Caller there are multiple newspaper clippings. When Cross looks at the one talking about his niece, it just does not talk about his niece. The clipping is on camera long enough to be able to read without freeze frame, and it's talking about things like police brutality and apartheid (actual word used), entirely unrelated to the fake headline and picture caption. (01:18:00)
Revealing mistake: When the Mack truck is trying to run Taggart off the road, the scenery on the copilot's window is an obvious chroma: first, it doesn't match the wide shots (bright green background vs cloudy and dull); second, it is repeated a couple of times. Also, when Taggart's car is cornered next to a mountain, the close-up shows a blue background.
Revealing mistake: When Alex is walking back from Mrs Hess' after shovelling her drive, you can see the "crooks'" car lights waiting for their Q to enter the street in the top left. (00:10:10)
Revealing mistake: Whilst Mima is opening the letters, there is a shot where she is sitting on her bed in the foreground of shot, and the TV is playing in the background of shot. On the shelf below the television is a game console with two controllers on top of it. The animation for the controller on the right is very weird. The right side is drawn longer than the left side, and its positioning on top of the console makes it appear as if it is hovering above it. (00:10:47)
Revealing mistake: When Jack is melting after being showered with acid, at one point, there's a very obvious cross-dissolve used to blend two shots into one as Jack is reduced into a skeleton. It almost works, except suddenly, the snow around him is slightly different. (Some impressions into the snow and whatnot appear during the fade that shouldn't, as does a few pieces of debris.)
Revealing mistake: When Magoo is skiing downhill, and the camera points directly at him whilst skiing, if you look to either side of his skis, you can see the tyre tracks of the vehicle towing him.
Revealing mistake: In the basement shootout, when a man is shot in the stomach, we see a close-up of his guts hanging out, and there's tape around it.
Revealing mistake: After the Djinn escapes and there's an explosion in the lab, you can see some stuff on the ground that looks like it's on fire. The objects are not actually burning, the fire is being produced by a burner. There's no smoke from the objects, which is a dead giveaway that they're not actually "on fire." (00:18:15)
Revealing mistake: At the end of the movie when Dusan sets the bomb for a time to blow up, he also sets his wristwatch, but if you look closely at the watch, he hasn't set it to a timer/stopwatch. (01:31:15)
Revealing mistake: When Mr. Eddy is shot in the head and killed, there is an extremely quick shot that you can catch of what is a puppet's head exploding from the shot, before it cuts to Mr. Eddy falling back dead.
Revealing mistake: When Brad and Caroline are running off in the taxi, across the border to PA, it is obvious that the lighting inside the cab are studio lights from the traveling crew, as natural moonlight would not reflect so strongly inside or out of the cab, at that speed.