Continuity mistake: Spot finds four other humanlike creatures and goes to them. Arlo is standing several feet in front of them. He begins to push some dirt by using his nose. A close-up then shows him using his nose to draw a circle around the five others but he is standing much too far away to be able to do this.
Continuity mistake: After Brad gets the electric shock, his shirt is completely clean but few shots later he has some burn marks on it.
Continuity mistake: The getaway car changes from a Peugeot Partner (1996-2003) to a Citroen C3 Picasso (2013-2017). (01:35:30 - 01:36:05)
Continuity mistake: In the early scene, when Maura is talking to the man in the corner, that she thinks is homeless, she stands up and has a green bag on her shoulder. When she asks for the sunscreen back, there is no sign of her bag. Then it's back on her shoulder.
Continuity mistake: When Jesse Eisenberg seeks shelter at John Leguizamo's house, John Leguizamo pulls a gun on him. Jesse Eisenberg grabs the gun from John Leguizamo and in the close up of this action it's a completely different gun. (00:40:55)
Plot hole: They have to invent Nitrotrinadium when they travel to the future because it was not invented yet, but was in the Russian drink in 2010, so should have already been available when they travel to the future.
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)
Continuity mistake: When Shaggy and Scooby are approaching the Demon as he eats, it is shown that he is eating from a platter of hamburgers and french fries. Scooby and Shaggy bump into his table, knocking the food all on the floor. When Shaggy and Scooby quickly put all of the food back on the table, it now has french fries and hot dogs.
Continuity mistake: When the woman is eating the bread roll on the train, the end of the roll switches from uneaten to having bites taken out of it and back again.
Visible crew/equipment: When Bryson and Katz are getting onto the Greyhound bus, a guy in a fluorescent jacket can be seen holding traffic up in the distance whilst the scene is filmed.
Continuity mistake: When Bianca takes Wes to the "thinking rock", as they talk and her hands are in her lap, her hair moves from over her left ear to behind her left ear and back, twice.
Continuity mistake: Near the beginning of the movie when Joy is in her airline's company uniform and getting ready to go to work, the knot on her scarf changes from loose to tight several times in the different shots.
Visible crew/equipment: When Davis comes out from the train with the headphones on in the subway just before starting to dance, a cameraman filming the scene can be briefly seen reflected on the train door's glass. (01:08:00)
Continuity mistake: When the two protagonists are introduced to the private room and watch Dan's video message, the clock in the background never moves despite the several minutes duration.
Continuity mistake: Lotte is in her room looking at the checklist for the parade. The size and angle of the quill pen change every time there's a cut. (00:14:40)
Continuity mistake: Théo shows up in class unannounced. The teacher tells him to sit next to "that girl", mistaking Daniel for one. The classmates of course have a cackle at that; the girl at the desk behind Daniel's laughs holding a pen in her left hand at first, right hand at the cut. (00:08:50)
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)
Other mistake: The town is Mt Barker. The red and blue ribbons on the sheep pen say Mt Baker.