- The idea of Jerry having a show in Japan isn't entirely far-fetched; his old college buddy even asks, "So, would have done it in Japan, but in English?", to which Jerry says he doesn't know. Japan actually does have a rather large English-speaking community, particularly Okinawa, so it wouldn't be entirely impossible for Jerry and George to do their in-universe show over in Japan.
- In "The Finale", the officer keeping an eye on the gang in lockup says that the Good Samaritan Law they were arrested for breaking was based on a French law. The gang was on their way to Paris when their plane went down, so even if they had managed to get there the same thing probably would have happened to them. Karma's a bitch.
- The sub-plot in "The Abstinence" of George becoming more intelligent by forgoing sex and Elaine becoming less intelligent for the same reason makes more sense when you remember the fifth season finale ("The Opposite"). There, the plot was that whenever George gained a success (got a girlfriend, got a new apartment, got a job), Elaine would suffer the opposite failure (broke up with her boyfriend, got evicted, lost her job) due to Jerry being "Even Steven".
- "The Summer of George" ends when George falls down the stairs. To reiterate, summer ends with fall.
- While Costanza is an Italian sounding surname, George's family are all Ambiguously Jewish. It's possible their last name is Sephardic.
- In one episode, Elaine gets bitten by a dog, and she fears she may have gotten rabies. After her doctor, who doesn't understand much english, cleans her arm off, Elaine asks him if she needs a rabies shot. The doctor thinks she's asking if she was shot by a gun ("Woof! Woof! Not, Bang! Bang!"). Elaine does get a rabies shot later in the episode, but only after showing symptoms of rabies! Okay, so this doctor who speaks poor english.... how many other patients has he misdiagnosed, or not properly treated due to not understanding certain questions?
- A rare in-show example has Jerry remembering the name of the woman he is sleeping with.