Character mistake: When Barry and Rob are in the record store discussing Evil Dead 2, Barry makes a comment about someone offscreen making shotgun ammo in the 14th century. That plot point refers to "Army of Darkness" (the third installment the Evil Dead series), rather than Evil Dead 2.
Character mistake: In every scene George is with Mary, she never once wears glasses. However, when he meets her coming from the library after he was never born, she is wearing glasses. George is shown how he has influenced all the people in Bedford Falls over his lifetime, but having Mary's eyesight degrade to the point of needing glasses isn't one of them.
Character mistake: In the very first scene in the film, the magazine covers are flashing up. There is an article called 'How to get a better bod in 5 days.' If you read the beginning of the article it says 'It Can Done.'
Character mistake: When we first see Sophie her body was slumped over (the spell to make her old) but later on in the movie, her back magically seems fine. (00:00:01 - 01:50:00)
Character mistake: When Billy comes back from high school to visit his 3rd grade class, Ms. Vaughn is teaching prime numbers. The board reads "1, 3, 5, 7, 11" with the words "prime numbers" below it. "1" is not a prime number and it is written on the board, and "2" is a prime number and it is not written on the board.
Character mistake: When the Tradewind arrives at the island, captain Hilliot says, "They might not be civilized," to which Richard replies, "Civilized: c-i-v-i-l-i-Z-I-D."
Character mistake: When Taj is getting ready to give Naomi a massage, she tells him she likes the song on the stereo. Taj replies "It is the White Barry" (meaning Barry White). It's actually a song called "Stumblin' In" performed by Suzie Quatro and Chris Norman.
Character mistake: Reina asked Cory if they could "do that thing" because it was helpful for her medical school training. Reina then put a raw slab of steak/meat across his forehead and made slits in the meat as well as jabbed at it. A medical student studying to become a brain surgeon should know about and practice the safe handling of raw meat. (00:23:10)
Character mistake: When Simon Dermott, a world-renowned museum security expert, steals the fake Cellini statue from the pedestal, he replaces it with a wine bottle, carelessly leaving his fingerprints all over the glass.
Character mistake: Stephen Baldwin is alternately referred to as Mark and Luke Dodge, without explanation as to which is his real name.
Character mistake: Mac's cousin says that even if Nick wasn't a cop, he'd have to hate Mac's guts. He says that Mac wears a Rolex and Nick wears a Timex - not true. Nick is wearing a Rolex, also.
Character mistake: When Mollie goes to Albert's office for the first time since having Mickey, Albert asks if he is walking yet, and she says no. In the next scene with Mickey, he walks, and is walking when he visits Albert's office.
Character mistake: When Adams is chewing out Altaira for flirting with his crew, he says that he is "in command of 18 perfect physical specimens." With him, that would make for a total crew of 19 on the C57-D. But the complete cast only shows 18 names, including Walter Pidgeon as Morbius and Anne Francis as Alta. (And discounting Robby and his human handlers). Thus it would seem Adams is off by three. He has only 15 under his command. I've tried counting them when they're in group shots, but can't see everyone.
Character mistake: In the beginning of the movie everyone shows up on Monday. When Rosenberg is taking attendance he mispronounces the girl's name. She corrects him and he says yesterday and the day before it was something else. That would mean they came to school Sunday and Saturday.
Character mistake: When Frank says to "V" that his mother died before he was born, "V" replies that she doesn't think that's possible. She is wrong. Although it may be uncommon, some babies ARE successfully born even after the death of its mother (usually with an emergency procedure).
Character mistake: Claudia says she is 40, her daughter is 16, it is referenced that it was a young pregnancy, however she would have been 24 when she had Kit, hardly abnormally young.
Suggested correction: 24 is still young and she doesn't say anything about being "abnormally young." Plus, in 1979, the mean age for first time mothers was around 25.5 (rising to around 28.6 in 1995), so she was on the young side of first time mothers. If she had said she was a teenager when she got pregnant, that would be a mistake.
Character mistake: Joe Dirt mistakenly refers to his 1967 Plymouth GTX as a Road Runner while talking to Jill at the carnival.
Character mistake: The map has the word Corazon missing the accent: "Corazón". This is so basic grammar that maybe it was done on purpose.
Character mistake: A space traveler would not be "going to Orion." The major stars in Orion vary in distance from the earth from 243 to 1,360 light years. Orion is only a constellation as visible from Earth; once you get away that far, the stars would not be in the same alignment as they are from Earth. They would have been going to a specific star, probably Bellatrix at 243 light years, as Taylor mentions being at 320 light years.
Suggested correction: I'm not sure what scene you're referring to, but I never heard anyone say they went to Orion. Taylor says they're on a "planet in orbit around a star in the constellation of Orion. That could be Bellatrix." To Taylor, who is from Earth, the star is still in the constellation of Orion.
I agree with your take, but I still think it could be interpreted as Orion's stars all being in close proximity. And I would hope they would know about the 320 - 243 light year issue.
Character mistake: On the proclamation announcing a plebiscite on a proposed "monarchy", the adjective "monarchical" is misspelled "monarchial".