Revealing mistake: When Franklin leaps out of the helicopter into the water, there is a shot from above that we see he is about to hit the water. To the left of him in the water you can see the water being split by a helicopter close to the water. The waves wouldn't have been created from the helicopter he just jumped out of because, a)The helicopter was too high up to make that sort of marking in the water and b)The waves are being made to the left of the helicopter. If it was the helicopter Franklin jumped from the markings on the water would have be directly below him or below the helicopter.
Revealing mistake: When Quinn is ambushed at his home one shot shows the female caretaker lob a grenade at him before he kills her. It falls to the pool. However, when it explodes, you can see that the explosion is above ground. A further shot shows the pool exploding after that.
Revealing mistake: When Seaborn Legend hits the Eindhoven Lion, some of the sparks come from places that are not making contact. (01:30:00)
Revealing mistake: Although the revelers in Dallas are celebrating the 4th of July, it's very obvious by the characters' clothing that the film was shot during cold weather.
Revealing mistake: When the Cyborg Master enters the police station, he shoots two police women before a third cop starts shooting back with a shotgun. The third shot he fires hits the wall behind the cyborg, and the entire wall wobbles as the squib goes off to make the hole in the wall.
Revealing mistake: When the partner-cop of Harrison Ford is killed there is shortly a scene where the dead guy is on the "table" at the hospital/morgue and you can see his jugular throbbing.
Revealing mistake: When the fireman goes to enter the fire truck that is on its side to rescue his friend, for whatever reason, the filmmakers sped up the film during his entry into the truck, it looks really out of place. (00:40:30)
Revealing mistake: When the car falls off the cliff it has no engine, clearly visible when the hood flies off. (01:12:10)
Revealing mistake: When Haru looks through the phone-book, you can see they took a real phone-book and simply glued a strip of paper that had 10 rows of fake names and numbers over a section of it (leaving space to make "Tanley, Martin" stand out). You can also see the name are briefly out of alphabetical order because of this. (And anything seen that is not covered by the strip of paper is a real person's actual address and phone number).
Revealing mistake: When Oz goes to hack into the Scream 2 website, the exact same footage of him inserting the "custom" disk is used when he hacks into the security system - same red light, same angle, even same PC tower.
Revealing mistake: When Nick is being followed by the PI, several times Nick's speedometer is seen to be at zero. (00:58:40)
Revealing mistake: When the needle is set in the pool of water in a stump to act as a compass the pool has been carved out with a chain saw very recently and clumps of the wrong moss set around the rim like it belonged there.
Revealing mistake: When Nick tells T. that he wants to give the money back they start fighting. Nick's sleeve gets almost ripped off, but before this happens you can see that the sleeve is stitched on rather loosely. (01:21:25)
Revealing mistake: When Earl crashes his Explorer through the police barricade, his car hardly gets any damage, proving the barricade is far more lightweight than a real one.
Revealing mistake: Near the end of the film, when Dacascos is fighting that other guy from Hong Kong, if you watch just after he does this smart kick, the guy's actually an Asian stunt double, and a lot shorter than Dacascos (best seen on the DVD putting it in slow motion just before).
Revealing mistake: When the Rangers arrive in the cave entrance of Maligore's temple (as Tommy cries "all right guys, this is it!") watch to the right of the screen, as Justin (the Blue Ranger) puts his arm against the stone cave wall and it wobbles, revealing it is a fake set wall. (01:11:40)
Revealing mistake: When Ernest is climbing up the chimney to get the mouse, the chimney shakes/wobbles slightly, showing us that it's made of rubber.
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: During the fighting scene outside the general store, Taggart hits one of the bad guys square on the nose two different times. After the second time, when the man is lying on the ground saying "Oh, my nose!", his hand's supposed to be holding his nose in pain but instead his hand is up around his forehead instead (his arm sort of blocks this but you can still see it).
Revealing mistake: It's obvious the snow is fake. You can see when Alex runs outside in his pajamas.