Revealing mistake: When Jack is doing a search for "Andi Garcia" on Google, the links show up in the searches he does as purple and not blue which means that they have already been visited, despite the fact that he's supposed to be doing this search for the first time.
Revealing mistake: When Flynn and Maximus are fighting to get the satchel, it flies off and gets snagged on a tree branch. But you can see it goes through the branch, and not around it.
Suggested correction: If you look closely, it is very clear that it doesn't go through the branch at all, but hangs from the side as it should.
Revealing mistake: When the 2nd BMW SUV is blown up on the dock, you can see the underside of the vehicle which reveals how they removed the drive shaft to help reduce the weight of it in order to flip it easier. There are also 2 jets of white gas seen coming from 2 pipes under the rear bumper which are what launched the vehicle end over end.
Revealing mistake: Inside the tunnel, Roy is on the car's hood, with the car swerving all the time. When the angle changes to a POV of the baddies he doesn't move, as if he was glued to the roof, revealing the security trick.
Revealing mistake: In the beginning, during the press conference, there's a press photographer taking pictures. He's obviously an extra with no experience in DSLR cameras at all, holding the camera around the flash and lens. He pushed buttons on the flash to "take a photo" and not one finger actually moves the real trigger on the upper right of the camera body.
Revealing mistake: In Frank and Sarah's first conversation her headset is on mute, shown by the fact it's blinking red. (00:02:25)
Revealing mistake: In the beginning scene when the dragons are attacking Berk, it shows several sky torch things being raised into the air. As one closest to the camera is rising, a Viking throws a burning stick at it to ignite it. If you watch it closely, you can see the torch starts burning first to the far left, well out of reach of the thrown fire. Even allowing for fumes igniting, the fumes nearest the flame should light first.
Revealing mistake: Horvath is trapped in the bathroom mirror, and after knocking on the mirror from the inside, a boy comes over. You can see that the shadow from the boy's shoulder is falling on Horvath, and when he turns and falls over, if you watch closely, you can see that the boy bumps into Horvath's arm. This is because the boy actor is standing in front of Horvath's actor to achieve the mirror effect.
Revealing mistake: During the scene where Kirk has an "accident" in his pants, the dog goes over to lick the stain. During this seen you can easily notice some sort of beef on the stain, probably to make the dog lick it.
Revealing mistake: During the scene where Jennifer Lopez does not have her body pillow, she has to use her friend/neighbor as a pillow so she can sleep. The nightshirt Jennifer is wearing allows you to see the fake pregnancy belly she has on.
Revealing mistake: Throughout the movie, people getting shot almost always don't have the shot angles line up with how they appear. This is especially obvious in the end scene with Hit Girl shooting the gangsters: she might shoot someone at an angle from the side, but the shot appears to have come from directly behind the person.
Revealing mistake: In the scene where Rachel McAdams goes to Patrick Wilson's office to explain why she left the bar so abruptly the night before, there are four TV monitors behind her as she does those weird charade movements. Only one monitor has a picture. The picture is of the New Jersey anchors of the job from which she was previously fired. Also, the characters in the picture never move.
Revealing mistake: On Gulliver's MacBook when he is plagiarizing , he has the wrong program active at the top (Finder for Macists), when he is typing on the keyboard. He also doesn't have a single word-processing application open, which can be viewed at the bottom.
Revealing mistake: Throughout the film the actors' breath is visible. This wouldn't be happening during the summer when the film is set.
Revealing mistake: The handheld device that Bob uses to adjust the satellite antennae is actually a very common label maker and printer sold in most Walmart stores.
Revealing mistake: The can of "Chernobly" is supposed to be from Moscow, and the lettering on the can contains at least one Cyrillic letter. However, the name printed on the can is nonsensical, using random Latin and Cyrillic letters in an effort to look Russian, but the letters don't spell a word and means nothing in Russian.
Revealing mistake: During the close-ups of Wiley when he's in the body and leg casts, it's quite obvious that both of his hands are made out of plastic.
Revealing mistake: When Declan and Amy miss the bus to Dublin the morning after the wedding, Amy walks out of the restaurant Poppie's Country Cooking with coffee. That restaurant is actually located in Dublin. (01:00:13)
Revealing mistake: When we see the man in the green shirt breakdancing, we can obviously tell that he is a professional breakdancer and not the same guy as the one breakdancing. The professional breakdancer is much thinner and reveals his face, which is completely different from the original man in the green shirt. (04:32:33 - 04:34:23)
Revealing mistake: When Dale is firing the nail gun, hitting the police car, the impact causes sparkles. Obvious movie effect. (00:44:05)