The Calzone - S7-E20
Continuity mistake: This mistake is in The Calzone episode. Towards the end when George walks in and his boss is looking around for the smell of calzones, George is holding a bag in his hand. In the next shot that shows the back of the boss's head the bag is now on top of a box that George is carrying. When it goes back to a close up the bag is in his hand again.
The Hot Tub - S7-E5
Deliberate mistake: When Elaine comes home and doesn't find Sean Paul there, she runs to her neighbour across The Apartment. The neighbour opens the door and stands outside it then the door slowly closes behind him. Suddenly, the door opens again with a swoosh without anyone being there. Because the camera switches angle right after this, it is apparent it was opened to gain this shot or to at least permit it continuity wise. (00:16:40 - 00:17:10)
Plot hole: When George and Jerry are discussing The Rye bread scheme, George says Susan is working late that night, so she won't be around when he sneaks The Rye into the house. But when George reels The Rye in with the fishing pole, Susan is standing there with her parents, wearing her coat. When did she get home? She couldn't have entered through the front door, because Jerry was there tossing The Rye up to George. And since it's a New York City brownstone, there's no backdoor that's accessible. There's no logical explanation for her getting into the house to see George reeling in The Rye.
Revealing mistake: When Jerry and Kramer are in the theater, Kramer trips and spills his cafe latte all over his shirt. But you can see the coffee stain on his shirt before he trips and spills it.
Continuity mistake: When Elaine crushes the beer can in Jerry's apartment, she leaves it on the counter. After she walks out of The Apartment, the beer can is on the cutting board.
The Sponge - S7-E9
Audio problem: When Kramer says "I read it in Wall Street Week," his mouth does not sync with the words. It looks like he said "Wall Street Journal."
Continuity mistake: The scene which George arrives at Beth's apartment in a messy condition to admit his remark was in jest, his shirt's hem and collar change between shots. During this scene, especially when he talks to Jerry on the phone, his collar is up and down; his hem is in and out of his trousers.
Factual error: At the end of the episode in which George and Susan get engaged, they are lying in bed together watching "Mad About You" on TV. However, at some earlier point on "Mad About You" it had been established in a crossover episode that Paul Reiser was the person who lived in Jerry's apartment before him and was an old acquaintence of Kramer's, meaning that "Seinfeld" and "Mad About You" existed in the same reality. On "Seinfeld," the show "Mad About You" could not exist.
Continuity mistake: When George and Susan are arguing over dinner about her cousin stealing the name Seven, Susan holds her glass up to her mouth in one shot. In the very next shot, the glass is on the table.
Continuity mistake: When George is at Susan's cousins' house complaining about them stealing the name Seven, its bright Daylight out. You can tell because the sun is pouring in through the windows. The woman goes into labor and they all get into the car to go to the hospital. At this point it is nighttime. When they finally arrive at the hospital it is broad daylight again.
Revealing mistake: When Kramer is getting slammed with his new super-powered shower head at the very end of the episode, it's blatantly obvious that the water is barely touching him - he's standing right next to it.
The Calzone - S7-E20
Factual error: When Jerry gets a speeding ticket, he asks Nicki to give the officer the registration. She gets a large piece of white paper from the glove compartment. That's what car registrations look like in California, where the show was produced. In New York, where it's supposed to take place, car registrations are the size of a driver's license, and are usually kept in the driver's wallet.
The Bottle Deposit (1) - S7-E21
Character mistake: When Jerry tells Kramer and Newman that they left their groceries under the hood of his car, he comments, "The AAA guy said I was this close to sucking a muffin down the carburetor." Jerry's car is a Saab 9000, which are fuel injected.
Continuity mistake: When Jerry and Elaine are talking in The Apartment, after George and Kramer go see the horse, the G+W Motorwerkes magnet disappears from the fridge.
Continuity mistake: In the start of the scene when Kramer tells Elaine that the armoire got stolen. When Elaine walks in from the right side she walks right past the armoire, and it still has the two blue straps on it so it's the same one. The gaffe seems to have been edited out in some versions. (00:09:50)
Plot hole: In the episode where Kramer decides to start sleeping like a Seal, he's with a girl. He falls asleep on top of her and she seems to think that he's dead. While breathing, your chest expands in such a way that if somebody were laying on top of you, there is no conceivable way that you could think that they are dead.
The Calzone - S7-E20
Visible crew/equipment: In the scene where Elaine questions her boyfriend in front of her apartment, look carefully at the end of the conversation. When her boyfriend turns and walks away, you can see where the green screen ends, with the crew members/cameras standing on the set. (00:09:25)
Continuity mistake: When Jerry finds The Soup Nazi's recipes in the armoire he hands Elaine at most 4 pieces of paper, but when the shot changes to Elaine the number of recipes in her hands has increased dramatically.
Answer: The name is Delores. He shouts that name at the end of the episode. Then in a later episode, "The Foundation", he runs into her. And he repeatedly calls her Delores.