Deliberate mistake: In the end scene at the TV set, Scrooge tosses a coin out the window, and the camera follows the coin as it falls in slow motion. The people in the control room also watch this on their monitors. Problem is, this is a live broadcast and filming/watching something live in slow motion is impossible.
Deliberate mistake: When Kalidor beheads a warrior and when Sonja beheads the wizard, both heads don't fall sideways as they should, but instead fly upwards, revealing they were tossed by someone offscreen - which looks more impressive, indeed.
Deliberate mistake: Instead of being a specific language, Edward has an English to Asian dictionary. I've heard this was done to prevent a particular time period from being established. (01:12:55)
Deliberate mistake: When Larry and the two moving men are first bringing the mattress through the doorway and it gets "stuck," the camera placement makes it pretty obvious that the mattress isn't really stuck. There's far too much wiggle room on either end for it to be "stuck." (Obviously it needs to be stuck for the scene to work... but still a weird inconsistency).
Deliberate mistake: After David jumps off the roof of the Firebrand building, it is discovered that he had been wearing a parachute, but this parachute was never visible on him at any point previously in the scene. Even when he was on the roof and after jumping, the parachute was nowhere to be seen. The parachute was too big to have gone unnoticed. It would have been visible whenever the shot was behind him and the straps would have been seen whenever the camera was in front of him. (01:17:30)
Deliberate mistake: The ghost opens Nikolaj's bedroom door an inch or so, yet there is enough light emitting onto the hallway floor for the door to be open about halfway. After the door closes, the light on the floor continues to gradually fade towards the closed door. (00:17:05)
Deliberate mistake: When Spidey jumps on the hood of the truck, Rhino squirts him using the wipers. Funny, but he can do that only because the detergent sprays forward instead of the angle actual windscreen washers are pointed at. (00:12:50)
Deliberate mistake: When Flash is at the coffee store, the pavement is dry. When he exits the place dressed as The Flash, it's wet for cinematic purposes, but a mistake nonetheless.