Revealing mistake: Very near the end of the movie, when the NOAA director is viewed in the helicopter as it approaches NYC, the image is reversed, verified by the David Clark logo on his headset being reversed. There are two different shots of this just a few seconds apart, and they are both reversed.
Revealing mistake: During the scene where Ron is playing the jazz flute, as he blows the flame out of the flute, you can see a hose running from out of his sleeve and into the flute, most likely supplying gas for the flame. In both shots of the flame, the hose can be seen.
Revealing mistake: Near the end, when Morgan Spurlock says "Why not do away with your Super Size options?" the water condensation runs UP the drink. (01:34:00)
Revealing mistake: When Shooter pins Mort against the tree with the shovel, you can see that it's a rubber shovel because it's bending around Mort's neck. [Mentioned on commentary]. (00:40:45)
Revealing mistake: In the scene in the alley behind the museum where Hellboy first encounters Rasputin, Sammael has its tongue wrapped around Hellboy's arm. When Myers enters and shoots at Sammael, look closely at Myers' hands. Not only does the gun fire without him pulling the trigger, but the gun does not even recoil.
Revealing mistake: At the fight scene in the cave, you can see the gun clip has no bullets in it.
Revealing mistake: Early in the film, when Hughes and another guy are walking past one of the replica WW1 aircraft used for the "Hell's Angel" scenes, you can see the ends of the cylinders of the modern air cooled engines they used to power it. The original aircraft (SE-5A) used a water cooled V8 which wouldn't have been visible.
Revealing mistake: This happens at the end of the movie. When No Good is tenderizing the meat with the brass knuckles, you can see that his hand doesn't come anywhere near the meat.
Revealing mistake: When Jenna is in her bedroom with her mom, as she points to the pictures in the article in Poise magazine, "30, Flirty and Thriving," it is blatantly apparent that it's not Jenna's 13 yr old hand in the close-up, but a much older body double. (00:05:25)
Revealing mistake: When Velma is running from the two one eyed skeletons she goes into what looks like a warehouse and the floor is all wet and in some places there are puddles. When the skeletons come they step into a puddle but the water doesn't even splash or ripple. (01:11:20)
Revealing mistake: Nearly at the end, the scientists find Alice's body at the waterfall, one of the men lifts up the cloth to take a look at her face. Her face is badly burned on one side and she is pronounced dead. However, take a look at the left side of her neck, you can see her either gulp or take in a quick breath of air. (01:19:05)
Revealing mistake: When firing the crossbow, Van Helsing runs out of arrows, but the bow's canister is completely full of arrows. In the same shot the canister spins once and they all disappear. (00:25:55)
Revealing mistake: In the jewellery store when the robbers are smashing the display cases they shatter before being hit with the shotgun butts.
Revealing mistake: When the demonstration crowd is assembling in the plaza, there's a yellow tram entering on the left hand side. Watch as someone walks across the tracks in front of it and disappears through the corner of the cab. The shot must be a composite of the crowd amassing and the tram shot separately and then overlayed.
Revealing mistake: When Huggy Bear meets Starsky and Hutch in the alley to supply information, there is a closeup on his face as he sits in his car and just before he leaves. In this shot, it is very obvious that the facial hair on his cheek is attached with a glue strip. (00:27:55)
Revealing mistake: In the scene where Evan wakes up and notices that he has no arms, right when you see the stubs you can see a faint shadow moving next to his head and moving on the headboard. This shadow is the shadow of his hand before it was digitally removed. (00:29:15)
Revealing mistake: When Ms. Norbury spills coffee all over her shirt, you can see the hand that is to the left is pulling her shirt up with her sweater and rapidly lets go.
Revealing mistake: While Blade's dangling a familiar off the roof, the familiar's phone rings (a Nokia 5210). Blade looks at the screen and sees the doctor's name. However, the display we see is a Nokia phone book listing with only one entry, rather than the "incoming call" display.
Revealing mistake: When the kid and the coach are throwing the little boxes of corn flakes in the air the kid's last couple of boxes were pre opened.
Revealing mistake: Throughout the extended scene where Ralph was training with Father Hibbert in pouring-down rain, both characters' faces were completely dry when they should have been completely wet.