Whenever we're shown the inside of Kramer's apartment via the peephole looking in, there's what appears to be a living room immediately in front of the door. However, when Kramer opens the door a wall is in its place, contradicting what the peephole reveals.
When Jerry is about to give George the card with the model number of the massage chair, George was still sitting on Jerry's couch. In the next shot, George appears right next to Jerry holding the card.
Elaine tells Jerry that she was unaware of Puddy's fur coat because they had never dated in winter before. However, in The Face Painter (1995), they attended an ice hockey game together.
On the show, Jerry lives on West 81st Street. However, when in Jerry's apartment Kramer tells Elaine and Jerry where they can find a man's fur coat, he says, "Just go down to 88th Street." Should have been "up" to 88th Street.