Continuity mistake: When Elaine is on the phone in Jerry's apartment, she holds the phone with one hand and lets the phone cord hang straight in one shot, and in the next shot she has the cord bunched up in her hand. (00:00:50)
Continuity mistake: While George is telling the whale story in the coffee shop, the ketchup bottle on the table disappears and reappears between shots. (00:19:00)
Continuity mistake: When Elaine and Jerry are confronting Testicoff about paying for the woman's hospital bill, in the view from behind Testicoff he puts his left hand down to scratch his pants. When the shot switches to a closeup of Testicoff, he is waving both arms above his head.
Continuity mistake: At the end of the episode, Kramer is telling Olive that he met someone else. Olive says "who is she?" and she puts her hand on her hip, in the next shot both of her hands are back on the counter.
Continuity mistake: When George goes into the suit shop after being told about the sale, he sees another man trying on the suit. George tells the man the sale is on Monday and the man takes off the suit coat and George is holding it in his hands when the saleswoman says the sale is on Friday. In the next shot, she has the coat and is hanging it despite never taking it from George.
Continuity mistake: In the episode with Courtney Cox, when she and Jerry are arguing over a can opener, a bottle of beer keeps changing positions whenever they cut back to Jerry.
Factual error: Near the end of the show, George is getting in a taxi in Central Park. The taxi medallion is on the side rear roof support. Taxi medallions in NYC are required to be on the front hood.
Continuity mistake: When Kramer is talking with Elaine and her coworker in the publishing office, his cigar appears and disappears between shots, as well as switches from his hand to his mouth in others, and from lit to not lit in others. (00:01:05)
Continuity mistake: When George is with his girlfriend at the coffee shop, the ketchup bottle on the table switches between being knocked over and stood up in different shots, despite nobody ever touching it. (00:03:10)
Continuity mistake: When Jerry opens the magazine to the article about him before handing it to George, the left side is mostly black with a picture and the right side is half black with "now" in big yellow letters. In the next shot of him handing the magazine to George, the page seen is mostly white with fine print and a small picture. In the next shots of George reading it, the magazine is back to where Jerry had opened it up to the first time.
Continuity mistake: When Kramer is on the Regis and Kathie Lee show, after he puts up the cofee table, Kathie Lee has her coffee mug in her hand. In the next shot, her hands are empty, and in the next shot it's back in her hand again.
Visible crew/equipment: When George and Elaine are in the cab, you can see the studio lights reflected in George's and the cab driver's glasses.
Visible crew/equipment: In the final scene with Larry David guiding Noreen off the bridge, a crew member's arm is visible in the bottom right corner of the screen. (00:22:30)
The Gymnast - S6-E6
Continuity mistake: When George is at his girlfriend's mother's house, the plates on the table switch around. Then the order he stacks them changes. When he picks them up, the plate with the chicken is in the middle with a plate with a napkin on top, then in the kitchen, the plate with the chicken is on top.
Factual error: In this episode, after accepting a free Armani suit from Kenny Bania, Bania insists that Jerry repay him by taking him to a nice restaurant. Jerry takes Bania to Mendy's, a Glatt kosher NYC deli. During the ordering process Bania suggests, "Oh, get the swordfish. Best swordfish in the city. The best, Jerry." Swordfish is considered an unkosher fish by Glatt kosher standards since it does not have scales, one of the essential criteria. It would therefore never be served at Mendy's.
Continuity mistake: Right after Jon Voight enters the taxi, Kramer sticks his arm in through the cab's rear side window, where Jon Voight was sitting. Jon Voight grabs the arm and bites Kramer on the wrist. As Kramer later was describing the incident to Jerry and George, he was pointing to a bite mark near his elbow.
Other mistake: When Mr. Bavalaqua is telling Jerry and Duncan the rules for the big race, there is a male extra right behind him who is mouthing Bavalaqua's lines as he's talking. (00:21:00 - 00:22:00)
Character mistake: When Jerry is being questioned on the lie detector test about "Melrose Place", the officer questioning him asks him two control questions that he responds to in full sentences. The questions should have been simple "yes" and "no" questions.
Continuity mistake: Kramer takes an awkward Polaroid of Jerry for his wall, but the photo on display is an ordinary print. (00:09:45 - 00:12:00)
Chosen answer: George does mention his brother in the episode "The Parking Space". They actually really never mention anything that contradicts the fact he had a brother though, it just isn't mentioned.