Character mistake: There's a note from "mother" on the wheel at the diner. Right beside it is an order with the wrong total. 2 hamburgers for $1.95 each. 2 fries for 90 cents and 2 drinks for 90 cents for a total of $5.70. The waitress put $3.70 for the total.
Character mistake: We see the lead driving on the motorway to get to the cottage. She leaves at junction 6 for Princes Risborough. Which means she is on the M40 that goes to Birmingham. When she arrives the host asks about the drive down and mentions the M4. This is a different road entirely, that goes to Swansea.
Character mistake: Near the end while in the caves Maggie is the first to go missing, but they use the name Gwen multiple times, the actress' actual name.
Suggested correction: Maggie Q is the actress and she plays the character Gwen Olsen.
Character mistake: Henderson asks the guy as he's leaving the room to get him some bourbon. They already drank in the bar and spat it out when they found out that everything had turned to blood, so it would still be blood.
Character mistake: In the highlighted newspaper article entitled 'DeFeo Son Accused' about the killings, the first sentence of the article ends with two periods. Also, in the 3rd sentence, the word 'psychiatric' is spelled "psuchiatric" with a 'u' instead of a 'y'. (00:01:05)
Character mistake: [Story 1: Hungry Joe] It isn't clear what blood test results the doctor receives for Joe, but Laura pleads that she "really needs to know what's wrong with her son" because "He eats, he eats, and he eats, and he never stops." The doctor dismisses Laura's concern and replies, "Growing boys eat... we'll see you in six months." The doctor should order additional tests. Blood tests can show "false negatives" and the appropriate blood tests may not have been ordered in the first place. (00:04:25 - 00:05:18)
Character mistake: It doesn't occur to our heroes (admittedly kids) that you don't need to understand German at all in order to read it out loud. It's arguably easier to read than English! The only inscrutable letter would be "ẞ" but Scary German Guy's right there for help. (True, this is essentially what they end up doing in the end, but they still come about it through a "you don't need to be of age to be a virgin" realization rather than the even simpler "you don't need to know German.").
Character mistake: Ginny is supposed to be put head first into the ambulance, not feet first. All the monitoring equipment is in the front of the head. (01:24:20)
Character mistake: Doreen/Mom told Rose she'd be back from the store "in a jiffy." Rose asked, "How long is a 'jiffy'?" and Doreen replied "in about an hour." "Jiffy" typically means VERY fast (perhaps as short as a nanosecond) and, even if people have different perceptions of how much time a "jiffy" is, an hour is excessive by general standards and does not reflect its true meaning. (00:32:50)
Character mistake: Shiwan Khan uses mind control to make Nelson commit suicide. Later, when Lamont is talking to one of his agents, the agent talks about a murder at the museum.
Character mistake: There are some musicians at different times in the movie. One of them is playing a moraharpa (traditional Swedish instrument, a predecessor of the nyckelharpa), but holding and playing it incorrectly. (00:38:37 - 01:39:45)
Character mistake: When Burt, Ernie and Spider go into the hall after questioning the zombie Burt says his own name instead of Ernie or Spider.
Character mistake: In the scene discussing the provenance of the mirror, the girl stated that Sherman marched to the sea in 1865. It was actually 1864.
Character mistake: When Chafuka is controlling the zombie Barry with her voodoo doll, he's supposed to be repeating her words so precisely that he even imitates her accent. But when she says "that darn fool paper, it fall on the ground," Barry repeats it as "The darn fool paper fell down to the ground."
Character mistake: When Harrigan is watching the surveillance video by Bill Paxton he states that the helicopter is a silver Alouette when it is actually an AS-350.
Character mistake: Remy mentions that the insects are part ant, cockroach and termite. She dismisses the mantis side, which allows it to mimic.
Character mistake: When Modoc is suggesting what type of blood to drink, he suggests pigs blood B-. Swine don't have B blood. They have A and O blood only.
Character mistake: Sally and Franklin's last name is Hardesty, but for some reason Franklin refers to their old home as the "Franklin place."
Character mistake: Set in Texas, the Sheriff threatens the wrongdoer with the gas chamber. Executions in Texas at that time were all by electrocution, namely by "Old Sparky," the electric chair. Texas has never used the gas chamber for executions.
Character mistake: In his opening prologue, Burt says the Graboids have been contained to the Northern Hemisphere, showing a map highlighting the Graboid attacks of the first film in Nevada and the second film in Mexico. However, it overlooks the Graboid/Shrieker attack in Argentina, in the Southern hemisphere, shown at the beginning of Tremors 3, an incursion Burt personally put down. It's not like it was classified - characters in that movie talk about it being reported by CNN, and characters in the Tremors TV series talk about it as well. And it's not like Tremors 3 is no longer canon, since Burt makes two references to being swallowed by the Graboid in that movie (which also becomes a plot point in Tremors 6).