Jerry works on new jokes for his stand-up routine. However, he previously used the same jokes in The Baby Shower (1991).
Jerry gives George the magazine with the review in it and he flips through the pages, stopping on a page with a black background. As the next few camera shots change, so does the color of the page that is supposedly being read.
The clown at the party says he's never heard of Bozo. When George says "How can you call yourself a clown and not know who he is?" He says "What is he, a clown"? Then afterwards says "You're hung up on some clown from the '60's, man." If he doesn't know who Bozo is, how does he know the decade in which he was most popular? Bozo has been popular before and after the '60s, so he probably just guessed when George was a kid. (He probably also meant it as an insult to George's age.)
A location shot plainly shows the Tom's Restaurant sign, not the fictitious "Monk's".
When George (Jason Alexander) is in the ambulance after fleeing the fire, the kids shout at him for leaving them behind, but some of them are clearly smiling.
George (Jason Alexander) claims to have knocked Robin (Melanie Chartoff) over as he was trying to get out of the apartment, but Robin clearly runs in from the bathroom in a red jumper, obviously not knocked down by George.
Elaine (Julia Louis-Dreyfus) is not impressed that Toby got the promotion all because of her pinkie-toe and she goes on about how useless the pinkie-toe is. Back in episode 5.11, The Conversion (1993), she had told her podiatrist how much she loves feet and especially the pinkie-toe.
When Kramer first appears, he says "Danke schön" which is German for "Thank you"--not a greeting.