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: When Johnny (Utah) and Samsara are in the ocean at night, the lighting appears to be in daytime. If you look at the surface when they come out of the little cave opening there is a bright sun-like shape.
Revealing mistake: One of the three last names that Maggie searches for is "French" but f you look at the results page, you can notice that the results are for the word "France." (01:08:10)
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: At Lake Balaton, DeLuca tries to escape by flying away in a helicopter, but he flies it using both hands on the cyclic stick in front of him (which controls only the direction of flight). However, to control the helicopter, he would also (at a minimum) need one hand on the collective lever (by his side), which makes the helicopter go up and down.
Revealing mistake: The idea is that the characters are in some super remote area where there are no working phones and nowhere to get help, but throughout the movie you can see a town in the background with buildings.
Revealing mistake: The protagonist is in the interrogation room. The clock on the wall shows 10:10, and stays that way throughout the scene, which lasts longer than a minute, close to two. (00:19:40 - 00:21:30)