Character mistake: Cliff tests Norm's memory by asking him who the bad guy in 'Herbie The Love Bug' was (presumably meaning the first movie, which was just 'The Love Bug, ' no Herbie in the title, and not the TV series that actually had the 'Herbie, the Love Bug' title). Norm answers Keenan Wynn, and is told by Cliff that is correct and that his memory is OK. Wynn was the antagonist in the second movie, 'Herbie Rides Again' (reprising his role from the 'Absent-Minded Professor'). The bad guy in 'The Love Bug' was played by David Tomlinson of 'Mary Poppins' fame.
Character mistake: When Otto tells Francis he has to put a horse down, Francis objects saying he's never killed anything bigger than a poodle, and that was an accident. However, in season 4 (episode 11), Francis accidentally killed Otto's pet cow. (00:11:30)
The Fall Guy - S1-E4
Character mistake: Thorny tells Ozzie that Clara Randolph is throwing a party. When Ozzie tells David and Ricky about that party, he calls her "Mary Randolph."
Character mistake: When Sue and her opponent switch sides right before her opponent smashes her racket, the score in games is 5-1. In tennis, you only switch sides when the sum of games is an odd number (4-3, 5-2, 1-0) for example.
Don't Bug the Mosquitoes - S2-E12
Character mistake: When the "Honey Bees" (Mary Ann, Ginger, Mrs. Howell) perform, Mrs. Howell (Natalie Schafer) messes up her lip-syncing throughout the number. But it is most noticeable at the very end when the girls put their heads together and say "buzzzzzzzzzzz" but Mrs. Howell is mouthing an "oooooooooo" which she changes to a "zzzzz" mid-way through the note.
Character mistake: While driving in a taxi, Fran says McDLT was discontinued in 1994, but in fact it was three years earlier in 1991.
Character mistake: Al is holding a picture of a 1965 Mercury Comet but says it is a 1972 model.
Character mistake: Near the end, when Michael reveals to Brennen he knows everything about him, he says, "I know everything about Tyler Brennen." Michael emphasizes "Tyler" as if it's a big deal that he knows Brennen's first name. Michael already knew Brennen's first name from the first time he met him, in Season 2, Episode 15 "Sins of Omission."
Character mistake: When Charlotte is looking at her wedding announcement in the New York Times, there is a close-up shot of part of the article. It says, in reference to Charlotte: "She is a writer and editor at Fashions Magazine in Manhattan". This is not true, nor has it ever been true. Perhaps the producers of the show threw that in, to see if anyone would notice. Also, the same article mentions: "The bride, who will be keeping her name..." and yet we never really hear Charlotte use the name York instead of Goldenblatt. (00:16:45)
G.I. Jessie - S2-E26
Character mistake: In the beginning of the pilot episode, Jessie told the cab driver that her father is in the Marine Corps. However, it is shown in this episode that her father is actually a lieutenant colonel in the Army. It's highly unlikely that Jessie wouldn't know what branch of the military her father was in considering how much she spoke about her military upbringing throughout the series.
A Breath of French Air (2) - S1-E6
Character mistake: It is mentioned several times that the Larkins' holiday to France takes place in August. Whilst on the beach, Ma Larkin says that Mariette and Charlie's first wedding anniversary is the following week. However, it is established in the previous two part episode, 'When the Green Woods Laugh', that their wedding date is the seventh of July, the same date that Pop has to appear in court.
The Joker's Flying Saucer - S3-E24
Character mistake: Vertigris tells Joker he planted a bomb in the Batmobile while it was parked in front of City Hall/Police HQ. Only in this instance, it wasn't. It was parked in the alley out back, the better to hide his bomb-planting from public view, so it's strange that he'd forget this. (00:08:15)
I Can't Make You Love Hannah If You Don't - S1-E4
Character mistake: When Olivia turns up at Jackson's house, she says, "That was my Saturday afternoon. This is my Saturday night!" which indicates it is the same day. But when Cooper arrives, he says, "Sorry for blowing off at you yesterday," which means another day has passed. However, at the Hannah concert, it is the same day all the while, so Cooper had got his days wrong.
The M.O.D.O.K. That Time Forgot! - S1-E2
Character mistake: M.O.D.O.K. refers to Hoobastank as "the Beatles of the late 90's." Hoobastank only released one album in the 90's, and they didn't become popular until after they released their second album in 2001.
Character mistake: When Mrs. Bun asks the dining lady if she has anything without spam in it, she forgot about egg & bacon, and egg, sausage & bacon. Those had no spam in them.
Ricky Asks For a Raise - S1-E35
Character mistake: After Tropicana nightclub owner Mr. Littlefield replaces Ricky Ricardo with Xavier Valdez, "the Konga King," Lucy, Fred and Ethel try to get Ricky's job back by going to the nightclub in a succession of different wigs and costumes, then leaving when they learn that Ricky is no longer performing there. At one point, Fred and Ethel enter the nightclub, posing as "Mr. And Mrs. Crumley." A disguised Lucy enters one minute later and is outraged to hear that Ricky is no longer there. Ethel then pretends to phone a friend to tell her to not come to the nightclub. Lucy says, "Attagirl, Mrs. Crumley." However, when Ethel had told the maitre d' she had a reservation for "Crumley," Lucy had not yet entered and therefore should not have known that name.
Suggested correction: During the point when Mrs. Crumbley wants to call her friend to get her friend to cancel her reservations as well, Mr. Littlefield says, "But Mrs. Crumbley," to protest as she walks to the phone to make her call. So he did say her name in front of Lucy, thus giving her the name to reply with, "Attagirl, Mrs. Crumbley."
When in Rome - S1-E3
Character mistake: Nobody in this scene knows how to dance the tango that is playing. (00:16:35)
The Purple Panther: Part 1 - S3-E6
Character mistake: In the song 'The World Goes Round', Stingy sings about dinosaur bones from the Stone Age (the second verse). The dinosaurs were wiped out about 65 million years ago while the Stone Age started 2.5 million years ago, an obvious time gap.
Character mistake: Geraldine's name changes from "Boudicca Geraldine Granger" to "Geraldine" but with multiple middle names from Mary Poppins with the surname "Granger."
Hookers, Hookers, Hookers - S8-E4
Character mistake: Gordon says that he never had sex with anyone Alan knows, yet in Season 3 he briefly dated Rose and according to Rose also had sex with her.