Revealing mistake: In the London scene, when the main characters prepare for the Centipede attack (the scene with the football players) there is a grey Land Rover which has a fake UK number plate on it. Plus since the film was filmed in Canada, the car also has left hand drive windscreen wipers.
Revealing mistake: When Maleficent freezes the people in the church, the actors can't help moving.
Revealing mistake: When the semi trailer is coming at them sideways down the highway, the trailer is missing 4 wheels. The tandems do not have their inner dual tires on them. Perhaps this made it easier to slide the trailer sideways.
Revealing mistake: When Krampus walks toward Max after he yells at him to give him his family back, wires are controlling Krampus' arm. (01:24:30)
Revealing mistake: When the crew does their first choreography practice with the new Bella, in the top left corner you see Amy and another Bella holding another girl in the air. You can see she's standing on a table, basically supporting herself.
Revealing mistake: In the Senior Citizen bus tour scene, just when the bus stops and almost hits the piece of construction equipment, Sofia Vergara is fixing her handcuffs. She adjusts them because one has visibly fallen off her wrist.
Revealing mistake: When Ted and John argue in New York, Ted walks off across the road and disappears behind a passing car. Look closely - Ted disappears a fraction too early.
Revealing mistake: When the Nazi doctor starts to torture Solo in the electric chair, he turns off all lights in the room except for a single dim light bulb over Solo's head; so, we know that the background is uniformly dark. Moments later, when Ilya comes to the rescue, a lighted control room appears behind the doctor, off to one side. After they strap the Nazi doctor into the electric chair, there is now a lighted control room directly behind the chair.
Revealing mistake: When Victor arrives with the drum he says is full of jet fuel, it's very obvious the barrel is empty by the way he's handling it.
Revealing mistake: When Rachel has a red turban on and is supposed to be bald, you can see her hair under the turban.
Revealing mistake: When Bradley come in the restaurant and ask the guest to apologise, he is starting to take the table cloth with everything on it but, while he is doing that, behind him you can see that the view of the restaurant it has a blue screen all over. You can even see the bushes outside.
Revealing mistake: From the sound made when the car hit the deer, as well as the deer's overall appearance, it was obvious the deer was fake. The fake deer's body was almost uniformly brown, but the "dead deer" on the road had a white underbody that went part way up its side and along its legs, which should have been visible on the "fake deer." (00:10:19)
Revealing mistake: When Verdean is scrolling the Wikipedia page for the Israeli wrestler "Johnny Jerusalem", the page itself is a well thought out fake one (the wrestler in question is non-existent), but the prop person who made this fake did not bother going all the way through editing the wording of the footnotes ("References" paragraph), that display instead the name of the real wiki page they edited as foundation. The webpage is an edit of the real Wikipedia page of The French Angel, the real life pro-wrestler who was also rumored to be an inspiration for the look of cartoon orc Shrek. All the names and dates have been slightly altered ("Paul Blowzier in New York" instead of Paul Bowser in Boston, "Carl Pohiello" instead of Karl Pojello, etc). (00:37:20)
Revealing mistake: At the cocktail party in his honor, Rita Richards introduces herself. Joaquin Phoenix's scotch is in a transparent plastic cup, and you notice what happens in most movies, here with particular clarity; when he brings it to his mouth, he does not take even a sip, but just pretends. (00:06:05)