Deliberate mistake: To make Jim Braddock look more heroic, Max Baer is portrayed as being very mean and hateful. In fact, the real Max Baer was an extremely pleasant man who was devastated when Frankie Campbell died after fighting him. Many boxing historians and sportswriters have complained about this inaccurate depiction of Baer.
Deliberate mistake: At no time can a player on the ice play without a helmet. It may be legal in professional hockey, but never in youth league games, world championships or not (This happens when the goalie comes out of the crease and takes his mask off to shoot his "knuckle-puck", as well as the penalty shot in the first movie.)
Deliberate mistake: The same scene of William Bendix at bat swinging and missing is used repeatedly in the film.
Deliberate mistake: When Rocky cuts Drago during round two of their fight, the punch actually hits Drago on the chin. His eye would not cut from that impact.
Deliberate mistake: During the sting attempt towards the beginning, Douglas confronts Snyder on the roof of the building. A helicopter rises up from nowhere without making any sound prior to that.
Deliberate mistake: When the Looney Tunes are playing basketball against the aliens, if you look in the stands the same cartoon characters are in different places at the same time. This happens a lot.
Deliberate mistake: In the end of the NASCAR race, Tripp and Gordon get into a crash making Gordon spin, but he somehow is still able to come in second place even though every other racer was right on his back when he spun. He wouldn't have been able to regain that much speed in that short amount of time.
Deliberate mistake: It wasn't Mike Eruzione shouting his own name that finally convinced coach Brooks to stop making the players do sprints. It was Mark Johnson, who smashed his stick against the glass in a fit of rage.
Deliberate mistake: In the championship game, when number three on the other team hits a home run, he never touches home plate. Home plate is where all of the players are crowded around (primarily the ones to the left of the scene). The player makes a "jump stop" at the batter's box. The Bears could have waited 'til the player went back to the dugout; the catcher, with the new ball in play, would have stepped on home plate, and the home run never would have counted.
Deliberate mistake: As the horse named "Sir Trenton", who is supposed to be a stallion, is galloping away you can see that "he" is a female.
Deliberate mistake: When Randy is playing with Agent Rodriguez's gun (after first meeting him), when he accidentally fires it, you can tell the film inexplicably cuts forward a few frames into the same shot, as Randy's body suddenly shifts position and the gun is facing upwards, rather than at an angle as it was the frame before.
Deliberate mistake: Right after Stevie and Marla attempt sex in his snowplow, the camera cuts to Marla buttoning up 3 buttons on her sweater which takes less than 8 seconds. However, in that same amount of time, making little or no sound to support his actions, Stevie manages to put on his shirt, zip up his pants, pull back up his coveralls, re-Velcro them closed perfectly all the way up to his chest, pull up and reposition the suspenders to the coveralls and be sitting calmly with both hands on his thighs when the camera cuts back to him. In less than 8 seconds, all silently and not moving the cab to the snowplow at all, no way. (00:32:20)
Deliberate mistake: During the final montage, we see Erik and Joyce in bed together, and the next sequence is of Teddy talking to his baby brother. This was to show that they got back together and had another kid. The mistake is that Teddy would've been a year older by that time, and so would've looked a little bigger, although there is also the fact that the actor who played Teddy (Dakota Goyo) was between 7 and 8 for the filming. (01:47:30)
Deliberate mistake: During the bathroom scene where Jimmy is trying to get the key to unlock himself from the handcuffs after the little Asian boy had knocked over the garbage can, the toilet paper roll should have had the cardboard tube attached to it upon reaching Jimmy and should not have various pieces of garbage on it.
Deliberate mistake: While Donnie is training at Front Street Gym, when Rocky repeats, "One step at a time, one punch at a time, one round at a time," the closeup of two children watching from outside the ring is a flipped shot, note the backwards Nike swoosh logo and Everlast ring rope spacer. (00:53:05)
Deliberate mistake: In the scene they show the newspaper headline "Tribe Gives Jays the Willies" at the bottom it says "Braves Lose to Mets" when in the previous scene, the scoreboard in the background says the Braves play the Rockies, not the Mets. Also, the Indians were playing the Baltimore not the Blue Jays.