Audio problem: When it cuts from Elaine to Kramer, the audio of what Kramer says is audibly split, as it sounds like he was speaking previously but it was cut off. (00:11:30)
Audio problem: As the doctor is explaining how he thinks there were other factors at play to stave off the infection, when he says "something perhaps..." his mouth/lips do not move.
Audio problem: The end of the word "bluey" that George is saying is cut off suddenly at a change to the shot of Jerry. (00:20:20)
The Pool Guy - S7-E8
Audio problem: When Elaine is arguing with George, she says the sentence "I like her," and the end of the word "her" is audibly cut off while she is still saying it. (00:11:55)
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."
Audio problem: When Kramer is telling Jerry about Little Jerry as he exits The Apartment, Kramer finishes his sentence with the word "jealous", and the S is audibly cut off in the middle, as if the audio was spliced there. (00:14:25)
The Apology - S9-E9
Audio problem: When Jerry is saying to Kramer "that was an hour ago", the beginning of the word "that" is cut off, and it sounds more like "at." (00:02:35)
The Apology - S9-E9
Audio problem: As Kramer is saying "come on, Jerry, how about a baggy swimsuit", the audio does not line up with the timing of his lips moving. (00:06:30)
Audio problem: When George says "and it will be easy because the receipt is in my good friend," the S in the word "because" is partially cut off at the end, indicating two different recordings were edited together. (00:18:35)
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.