Revealing mistake: In the scene where Axel throws the art dealer's henchman onto the buffet table, if you watch carefully (or use slow-mo) you can see the stunt double pulling off that manoeuvre. There is also a stunt double being thrown over the table.
Revealing mistake: There is a shot from the Terminator's POV, before he rams the blue car with the semi truck, in which you can see that the car is already damaged. No slow-mo is required to see this, but it is a blink-and-you'll-miss-it shot.
Revealing mistake: When Nancy is running up the stairs in her house to escape Freddy for the first time her foot hits the steps and go through the steps into some goop. Look at the steps above that step and you can see the pre-cut holes where the next sets of goop will be. (00:39:10)
Revealing mistake: When Kirk and Kruge are fighting, a piece of the cliff breaks away and wiggles down the side of the cliff rather than falling like a rock. (01:22:55)
Revealing mistake: When Charlie sets the mens clothes on fire, burning gel is clearly visible on their clothes. (00:38:30)
Revealing mistake: As Vicky and Burt are driving down a dirty lane, through a row of corn, you can see fresh tire tracks in the mud from a previous take. (00:34:35)
Revealing mistake: When the Russian pod is launched, a wide shot shows the Monolith at top/right with Jupiter in the background and both the Leonov and Discovery at bottom/right with the pod nearby. Just before this shot ends, all three spacecraft vanish, leaving only Jupiter and the Monolith for a very short but obvious moment. (01:04:35)
Revealing mistake: Almost every time a floating robot explosive that is chasing the police cars is seen, you can see a wire that is pulling them.
Revealing mistake: During the movie, the ninja crushes with their bare hands a golf ball (in the opening fight) and a billiard ball (in the fight against Case). Both times the ball is replaced by a shell filled with talcum powder. It's especially conspicuous in the case of the cue ball, because the previous 'stunt' involved slicing one in half and the ball looked nothing like the one she 'pulverizes'. (00:04:00 - 00:38:35)
Revealing mistake: The robber who kills Billy's mother is shown cutting her throat but with the flat side of the blade. Moreover real blood doesn't ooze out so thickly, indicating it was makeup.
Revealing mistake: The scene with one of the girls in the Pi house undressing on the TV was filmed with a handheld camera. Lewis tells Lamar to pan the scene right which it does. Cut to the scene of the woman undressing and the scene is shaking, like someone is holding the camera. These should be stationary shots. We even see the camera that is filming the shot and it's strapped down with a periscope.
Revealing mistake: The ammo box that is removed from the purse is for blank studio type cartridges, and not ballistic ammunition.