Continuity mistake: Jerry called his parents back to tell them about Myra's dead. When his dad at the end of the scene says "You know what this funeral's gonna wind up costing me?" Barney Martin is leaning his head against his hand all of a sudden. (00:12:50)
Continuity mistake: At the family dinner, Jerry's mom mentions horses for the first time. Reaction shot on the old lady saying "yeah, yeah", and cut to a wider angle; she is now all of a sudden leaning on her right arm. (00:06:50)
Continuity mistake: The first time we see Jerry's dad, he's passively taking his wife's whine about The Jacket, remote control on his chest and hands crossed on his belly. Cut, and he is sitting with his arm by his sides. (00:01:00)
Continuity mistake: Kramer leaves with the cantaloupe saying "Well, I am taking this back"; not only he grabbed the fruit during a cut at breakneck speed, but the towel on the station changed also position. (00:17:00)
Continuity mistake: Kramer and Jerry are talking about Marlene. Kramer says "Why would George want to deprive you of pleasure? Is it just me?"; he raised both hands chest-high. At the cut, his right hand is lowered. (00:16:00)
Continuity mistake: In the very first shot of Jerry's conversation with George's ex, behind the pile of books you can spot a big lemon slice on the rim of the glass. The slice is then gone from that spot (it's inside the glass now, submerged by the drink), but between shots it is back on and then off again. (00:08:00)
The Jacket - S2-E3
Continuity mistake: When everyone gets up from the lobby seats talking to Alton, George's coat is folded on his arm in two different ways that alternate between shots. (00:17:40)
The Statue - S2-E6
Continuity mistake: When Kramer gathers the old clothes, shoes, hat from the cardboard box on Jerry's table, they keep changing position in his arms between shots. (00:04:30)
Continuity mistake: Elaine tells Jerry about the ex with the unclean bathroom. At the end she puts her lollipop in her mouth twice in two separate shots. (00:07:00)
Continuity mistake: When Jerry says that Manya's widow is moving to Phoenix, Julia Louis-Dreyfus ' teacup turns 180° between shots. (00:16:15)
Other mistake: The previous episode "The Deal", was supposed to be the season (and possibly series) finale, however it was aired out of order. Therefore in this episode and the next without explanation Jerry and Elaine are not romantically involved anymore, and Kramer pitches cable to Jerry as if he never had it before, mentioning "The naked channel" that was sorta the triggering factor of "The Deal" 's plot.
Suggested correction: As you said, the episodes were aired out of order. That doesn't make it a mistake because if you watch the episode in the order they were produced, there would be no mistake.
Other mistake: When George is taking off his sweater revealing the chocolate-smeared shirt, a woman in the background hilariously stares, looks down at the shirt and then eyerolls. She is behind him, though, and can't possibly have seen the stain. The shirt looks fine from the other angles. (00:16:30)
Continuity mistake: Kramer tries to stop Jerry from running towards the door. "Agent Stone" in the following shot has his badge in the left hand (was in the right earlier) and reaches with the right for his gun under The Jacket. But there's another shot, with cornflakes and other things being blown up by bullets, when Stone is still showing his ID in the right hand. (00:09:00)
Continuity mistake: In the shot when she protests that the husband with the chipper name is only a Kennedy by marriage, Elaine is holding a paper towel, not quite in continuity with what comes before and after. (00:01:35)
Continuity mistake: The doctor is examining George. George yells into the stethoscope so he takes the buds off his ears. Not just that; he removes the instrument and puts it around his neck. George then freaks out and starts naming various odd and even rather harmless conditions; the doc is wearing the stethoscope again. Flirting with Elaine you can see the instrument sorta shuffles around, with part of it exposed and part of it under the scrubs' collar, now the left side, now the right side. When Jerry breaks off their idyll with the Romeo and Juliet reference, the stethoscope is back around his neck, only to be again in use when George asks "With a knife?" (00:08:00)
Continuity mistake: When the doctor tells George that he can have some ice cream, he touches his arm. Difference is, in the first shot the clipboard is in the right hand, in the close-up it's in the left hand. (00:09:20)
Revealing mistake: When the two paramedics get off the van to duke it out, look at George lying down in the stretcher. The pillow behind him bears in the last two shots faint purple coloring marks washed out from Jaso Alexander's makeup. (00:18:30)
Continuity mistake: Tor is introduced; in the reaction shot on Jerry and George to the weird hug with Kramer, Jerry is holding his own leg with his both hands. In the wider shot he just uses his left and with nothing else in it. (00:13:30)
Continuity mistake: During the visit, whenever George asks questions about hot water (can I use it on my face, can it be lukewarm) his hands have a sudden position change between shots. (00:14:50 - 00:16:00)
The Revenge - S2-E7
Continuity mistake: During Elaine's amazingly off-putting flirting with George's boss, she starts mentioning how people don't say "Bless you" as they used to. She is gesturing with her right hand pointing a thumb -but before her "Have you noticed that?" is over, she is already in a new shot with hands joined and fingers entwined. (00:16:00)
