Factual error: The time period of the movie is 2054. There is an election day (April 22nd) that is on a billboard and then announced as a Tuesday. However, April 22nd, 2054 is actually on a Wednesday.
Factual error: After the intruders flood the panic room with propane, Jody Foster's character gets a lighter and ignites the propane causing it to burn along the ceiling. This would be impossible as propane is heavier than air and would sink to the floor rather than rise up to the ceiling. Lighting a flame in that room should have caused anyone in the room and on the floor to be engulfed in flames almost instantly.
Factual error: All the scenes which are supposed to play in Zürich were being shot in Prague, the capital of Czech Republic. The director didn't choose Zürich because the city was too clean for him. The signs on the walls are sometimes written in Czech language, and the people speak German with a strange (Czech) accent, not like someone from Zürich.
Factual error: In the scene where Noah analyses the tape, he says that the 'timecode' seems to be invalid and says that every tape has a track where you can see what device was used to record it, etc. The video technology explanation originates from the original, Ringu, with the plot of The Ring changed to make it more applicable to average Americans. But a VHS tape does not have a special track for timecode. It is possible to lay a timecode onto the tape in either an analogue form via a special audio channel, or as digital information on lines 16 and 18 of the vertical interval. But this 'timecode' is only used for professional video editing. A standard VCR, like the one they were playing the tape on, does not use this, and therefore makes Noah's explanation a minute of utter nonsense.
Factual error: When Ellen gets married in 1907 she is 20, but when she disappears in 1950 she is 70.
Factual error: After Joe spends sometime underwater in the bus, he goes into the village and pulls a picture of his wife out of his pocket to show the village people. After getting that wet, a picture will not be intact, and it would pretty much be stuck together.
Factual error: The boardwalk is twice as wide as the real Long Beach boardwalk. The ramps on the real Long Beach boardwalk run parallel to the boardwalk. The movie's boardwalk ramps run perpendicular to the boardwalk.
Factual error: The fake Rheya tries to kill herself by drinking liquid oxygen. The liquid shown is green, viscous, and foaming and looks a bit like the monster's body fluid in Alien. Liquid oxygen is colorless, non-viscous and doesn't produce sticky bubbles. (01:00:25)
Factual error: The train to London that everyone gets on is a French TGV. The TGV doesn't run through the Channel Tunnel, only the Eurostar trains do.
Factual error: In the close up shot showing the record on the record player, the label correctly identifies the song that played as Benny Goodman's "Sing Sing Sing (With a Swing)" but the label also states it is a "Swing Classic," a classification only used when the record was later reissued. The label is inappropriate for a World War II time frame. (00:16:05)
Factual error: During the fight just before Elvis uses the alcohol, Bubba Ho-tep exclaims a series of Egyptian hieroglyphs which are translated as "By the unwinking eye of Ra." The symbol on the far right is not the Eye of Ra (which faces right) but the Eye of Thoth (an identical symbol which faces left). (01:18:10)
Factual error: The Point & Shoot Camera Sy uses throughout the movie (Minolta Freedom Zoom 150) has a lit in-viewfinder readout. The real camera does not have any fancy readout, just a thin circle to help center and frame your image.
Factual error: In the scene where, Clint is examining his scar, the scar is misplaced. It should run from the top of the sternum between the collar bones to the bottom of sternum, mid diaphragm.
Factual error: John supposedly goes to Chicago to talk to a mothman expert, but it shows the two of them walking into The Mellon Institute which is actually in Pittsburgh.