When David is describing to Elaine that it would be his and his wife's anniversary soon, Cary Elwes' British accent is noticeable.
When George is sitting on the couch talking to Beth in her apartment after Jerry and Elaine have roughed him up, the left side of his collar goes from up to down in various shots, and his shirt is alternately wrinkled or smooth. When he gets up to talk to Jerry on the phone his shirt is tucked in and when the conversation ends his shirt is partially untucked and the left side of his collar is up again.
When Elain is careening down the list and and stops the car in excitement, the interior shot shows a lot of cars behind her. Then it switches to an exterior shot of her car stopping, and there are no cars behind her anymore. Back to the inside, and the cars are back.
When Elaine urges Jerry to go over to Beth's, she picks up his jacket. The jacket is next seen in his hand without him taking it.
Beth's (Debra Messing) ex's apartment number is 5A and the door opposite shows 5B. The same doors used for Jerry (Jerry Seinfeld) and Kramer's (Michael Richards) apartments are used.
Cary Elwes's speech waivers between an American accent and his native British.
When Kramer walks into Jerry's apartment after the audition with Mickey, you can see a microphone hanging down from the ceiling for a brief second.
Jerry comments how Kramer looks like Frankenstein in the skinny jeans he wears. However, Jerry really means Frankenstein's monster as Frankenstein was the doctor who created the monster.