Character mistake: The Sheriff calls for Drayton Sawyer to bring out his son Jed (Leather Face) in the movie's opening scene. But it's long been established that they're brothers.
Suggested correction: This is meant to be a direct sequel to the original film, and ignores the other sequels. And if memory serves correctly, the first movie never made any mention of them being brothers. (I just checked and the Texas Chainsaw fandom Wiki backs this up - the original film makes no reference to them being brothers.) So therefore, it is not a mistake if this movie re-writes him as being Leatherface's father.
Character mistake: The Fifth Amendment Double Jeopardy Clause does not apply. Libby could be convicted of 1st Degree murder when she gets out and pursues Nick. It doesn't really matter to the plot, however, because it was what Libby believed to be true and motivated her. Further, she ends up shooting Nick in self-defense. So it's all good.
Character mistake: When we see the door to Elisabeth's, her name is spelled with a s. Later when Nick looks her up on the computer, it's spelled Elizabeth.
Character mistake: Twice over in the movie (when Healy wakes up and when March at the end of the movie drives to his place) billboards for The Comedy Store appear. The program of the evening features comedians such as Tim Allen, Richard Lewis, Robert Klein and "Elaine Boosler." So they misspelled Elayne Boosler's name. (00:10:50 - 01:48:35)
Character mistake: Mia's Sea-Monkey, in a vertical position, was shown sinking to the bottom the jar. It isn't clear if the Sea-Monkey was dead or if Mia was referring to it when she said, "She's gonna freeze to death, Aiden", but Mia should have known how to properly care for her Sea-Monkey (or refer to the instructions) and, realizing the room was too cold, should have done something - such as wrapped a towel/blanket around the jar and/or moved the jar to a warmer location (e.g, near the fireplace). (01:22:33)
Character mistake: When the sheriff confronts Charlotte after she has shot at the bulldozer operator, he tells her that her gun is unlicensed, but he will overlook it. Louisiana does not have, and never has had, any form of gun licensing or registration.
Character mistake: Casanova refers to Cross's gun as a "Glock," but it is a Sig.
Character mistake: Daphne's mother is the one who pressed her husband to tell her the truth, but she is cheering when he says about the basketball anecdote that it was 'real', when later he corrects himself saying "real-ly me, disguised as a mascot." (00:17:25)
Character mistake: Dr. Bessner tells Linnet that the Eastern statue she'll see at Abu Simbel is 'the vocal statue', which emits a sound at sunset. The statues the doctor mentions are the Colossi of Memnon, over 500 kms north of Abu Simbel, so the movie here mixes up two very different monuments. (00:49:30)
Character mistake: When Joe and Marie are going over files in the old school, Joe finds a staff letter announcing the enrollment of Amanda Pryce. The top of the letter is dated 1984. However, Joe then proceeds to ask Marie to search for Amanda's file, and tells her to search for the year 1986.
Suggested correction: It's possible the incident happened up to 2 years after her enrollment (starting as a freshmen and the incident being when she was a sophomore or junior).
Character mistake: When Ramathorn and Farva pullover the Plymouth Voyager, Ramathorn radios in and says they have a Plymouth Voyager, Vermont plates Alpha, God, Mustard, 1, niner, decade, china. When Farva gets out of the car to call the driver a chicken f**ker, you can see the licence plate, Vermont plate '1 9415'. Ramathorn radioed in the wrong licence plate number.
Character mistake: When David Frost interviews the fictional actor Bryan Martin, he adds a last question to the interview saying "before you go" and acts as if the guest is not gonna stay (as it often happens in talk shows, when some guests, especially the more famous ones, leave after their bit is over). However Martin is staying and in fact there is a special mystery guest a bit later that makes sense only if he is in fact staying. (00:02:00)
Character mistake: On the way to Jerusalem, Poirot says that "that man, Weizmann, put it rather well the other day, before Lord Peel's commission", and gives a famous quote about the world being divided in 'two places' for the Jews (those where they are not allowed to live, and those they cannot enter). The movie takes place in May 1937, and Chaim Weizmann's quote is from November of the previous year. 6 months are hardly "the other day."
Character mistake: Over the phone, Julie told her sister Sara, " I got them [parents] a bouquet", pronouncing the "T" in bouquet. Bouquet has French origin so the "T" is silent. Bouquet is properly pronounced like bow-kay (American English) or boo-kay (British English). (00:00:55)
Character mistake: When Marie joins Bourne in the bathroom while he's getting medicine, Marie says he's burning up. She gets a washcloth, wets it and dabs Bourne's neck. She only had what couldn't have any more than a tablespoon of water and dabbled it less than a few seconds. It couldn't have had any effect on someone who was burning up.