Revealing mistake: The picture on the wall of a younger Mike on a horse shows his groin against the horse's neck right below its ears - obviously photo-edited/photoshopped. (00:04:29)
Revealing mistake: Lower-third shots of the aquarium in the background at the Delaware Raceway's sports lounge were often blurred and did not look like they matched full views of the aquarium. (00:36:05 - 00:36:34)
Revealing mistake: When Alana is walking toward the students, the hedges are mostly dark green, sheared level across the top, and reach to her elbows. Later (after Gary tells Alana he will take a mirror), the hedges turn mostly yellow and flower-like across the top, are quite uneven, and are as high as her shoulders in spots. (Use of a green screen is apparent). (00:00:40 - 00:01:26)
Suggested correction: One look at the scene make it apparent this entry is totally incorrect. The bushes look natural. The yellowness is just colour grading. There is no sign of green screen usage whatsoever. It would make no sense for this film, especially if you realise that director PT Anderson is known to be very much against the use of any sort of VFX or green screening.
Revealing mistake: The blue framed window the girls walk in front of after exiting the VW bus parked along the curb is presented as part of an extension of the house, but not when there's a front view of the entire house. The windows are actually aligned with the front door. (00:11:44 - 00:15:00)
Revealing mistake: In a sudden downpour, "rain" falls vertically, across a single line. (00:18:28 - 00:19:44)
Revealing mistake: When Paolo tells Patrizia "I do have something on my father", you can plainly see the separation between the frowned forehead of Jared Leto and his "bald cap" prosthetics. (01:15:30)