Trivia: In every episode of Seinfeld there is a Superman reference somewhere.
Suggested correction: This is a myth and not true. Even if you count seeing the Superman fridge magnet or Superman statue as a reference, they didn't appear until season 4 and 5.
Season one had a few and one of them is episode 15 The Stock Tip. To quote George: "I never heard him say anything really funny." Jerry: "It's common sense. He's got super strength, super-speed; I'm sure he's got super-humor." "Either you're born with a sense of humor or you're not. It's not going to change. Even if you go from the red sun of Krypton all the way to the yellow sun of the Earth."
That wasn't the point of my correction. The trivia is wrong because not EVERY episode has a reference. I didn't say no episode prior to season 4 or 5 had a Superman reference. I only said the magnet and statue didn't appear until season 4 and 5, so even if you want to count those objects as a Superman reference, it doesn't apply to season 1-3.
Continuity mistake: In this episode, George asks Russell if his last name contains a "y" and Russel answers that it doesn't. However, Russel is credited in this and subsequent episodes as "Russell Dalrymple."
The Stakeout - S1-E1
Visible crew/equipment: Stage lights are reflected on the coffeepot when the waitress serves coffee.
Suggested correction: You can see lights reflected on the coffee pots, but there is nothing to indicate they are stage lights as opposed to the diner's lighting.
Other mistake: While Jerry is looking out the window, to his right, there is a Yankees baseball cap on top of his mini basketball hoop, above his computer monitor. Jerry in real life is a Mets fan, and he alluded to being a Mets fan on the show as well (taping a Mets game, wearing or showing Mets paraphernalia). In no universe would a Mets fan have a Yankees cap on display and vice versa. This was before George got the job at the Yankees so that can't explain it. Was it just bad set design and props? (00:14:22 - 00:15:30)
Suggested correction: There's a Yankee hat in many previous episodes. It's never mentioned where it came from, but it could be a gift or signed or hold significant value to Jerry as opposed to him buying himself a Yankees hat to put on display. And that's assuming Jerry in the show is such a Mets fan that he wouldn't like the Yankees as well.
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.