Deliberate mistake: The morning after the flyers are spread, Buster is sleeping in a drawer. When his alarm clock goes off, he hits his head at the top of the drawer, but later on, he can be seen standing up in it, easily visible when he is putting his coat on. The drawer obviously became wider for him to stand up in it.
Deliberate mistake: Some odd legal matter must be involved here; when we see the two ladies look at the viral video, one tells the other to look at the "Youtube" sensation with over a million views, but the website shown is not Youtube but an obvious knockoff version. (01:19:30)
Deliberate mistake: When Sook-Hee is first shown her bed chamber, just after Sasaki leaves, she slides open the door to Hideko's room to look inside. After a 5-6 second silence, a thump sound is heard and Sook-Hee quickly closes the door. Later in the movie, when this same scene is shown a second time from Hideko's perspective, the thump sound, which is revealed to be Hideko banging her doll against the wall, occurs 11-12 seconds after Sook-Hee slides the door open. (00:06:38 - 01:32:33)
Deliberate mistake: The movie is set in the late 50s, but Howard Hughes is dealing with his plane crash and the senate hearing about the H-4 Hercules prototype. Those are events from over a decade earlier. However, it should be noted that the initial disclaimer of the movie is "Names and dates have been changed."
Deliberate mistake: It is unlikely that Kimmel shoving/ramming the beer bottles on the table using his dish and piece of steak in his right hand would shatter the beer bottles into such small pieces (or at all) like he did. (00:36:55)
Deliberate mistake: After Jim completes the awakening protocols, he is shown to his cabin because his door lights up. That's fine if he's the only one there, but he's not supposed to be. Presumably, there would have been hundreds of other people awakened as well, and the ship can't show all of them to their cabins by lighting their doors at the same time. But reviving every passenger separately and showing them to their rooms one at a time seems highly inefficient.