Revealing mistake: When the mall Santa lands in the Bundys' back yard, everybody looks toward the back, and when Al looks forward, he cracks a smile although he's upset about the matter. Ed O'Neil admitted he couldn't contain his laughter.
Movie Show - S7-E21
Revealing mistake: When everyone is standing at the snack bar eating all the food you can plainly see all the candy boxes are empty and already open even though they were sealed when the cashier put them on the counter.
Poppy's By the Tree (2) - S2-E2
Revealing mistake: When Al is blocking the killer's axe with his suitcase and they struggle for it, it is obvious that the axe is made of rubber, as the handle keeps bending.
You Better Shop Around (2) - S5-E22
Revealing mistake: Marcy is stacking cartons of eggs in her arms. She turns around and a carton falls on the floor making a busted egg sound although the cartons are obviously empty.
Revealing mistake: When the bailiff pours rum into the judge's jar, it's obvious that there's nothing coming out of the flask. (00:13:05 - 00:14:10)
You Better Shop Around (2) - S5-E22
Revealing mistake: When Jefferson starts to shove the 'regulation Foodies cart,' it's very obvious that the actor makes the shaking movements of the cart by himself. (00:08:05)
I Can't Believe It's Butter - S10-E13
Revealing mistake: When Griff drinks the gravy right before calling "Butter", his glass is empty.
Revealing mistake: When Kelly enjoys her triumph at the middle of the stairs you can see a shadow on the wall right from her - obviously Al stands behind the wall waiting for his cue. (00:19:00)
Revealing mistake: Peg is making Al a steak. Problem is the burner isn't even on.
Revealing mistake: Kelly is standing by the clock on the stairs. You can see Al and Peg's shadow on the wall waiting for Kelly to come up the steps, so they can come down. (00:02:59)
You Better Shop Around (2) - S5-E22
Revealing mistake: When Al 'bowls' Jefferson out of the way you can see the stuntman jump high and fall back into some kind of holding wire. It's an annoyingly bad stunt. (00:19:45)
Poppy's By the Tree (1) - S2-E1
Revealing mistake: When Al, Peg, and the kids get to their room, notice the "hole" in the blanket on the bed. It's there the entire episode so at the end, the killer can shove the machete up through it.
Revealing mistake: At the start of the episode, Peg is making popcorn on the stove. It's making a sizzling sound like she's really popping it but the burner isn't even on.
Desperately Seeking Miss October - S4-E7
Revealing mistake: In the scene where Al and his Dad (both played by Ed O'Neill) are sitting on the couch side by side watch the lines of the cushion in the middle. Every time one of them moves you can see where the two separate shots are overlaid. (00:14:15)
Guess Who's Coming to Breakfast, Lunch and Dinner - S10-E1
Revealing mistake: Near the beginning when Al is looking for his magazines under Bud's bed, a large shadow of someone crosses over him showing someone in production crossed in front of the lighting.
You Better Shop Around (2) - S5-E22
Revealing mistake: When Marcy is stacking the cartons of eggs in her arms, you can plainly see that they are empty cartons.
Revealing mistake: When Kelly goes for her commercial, you can see that there is a stocking head cover to make her appear bald.
Im-Po-Dent - S2-E19
Revealing mistake: Bud and Kelly put Tang in glasses. Al says "what are you hiding?" They quickly "drink" it but the glasses are empty.
Revealing mistake: Peg is making popcorn on the stove. It pops even though the burner isn't even on.
Weenie Tot Lovers & Other Strangers - S5-E18
Revealing mistake: When Peg opens the last weenie tot box, notice that only a ticket falls out. Meaning all the boxes had no tots in them just tickets.
Answer: Bud's date is a foreign exchange student and Kelly was wondering what was sent to the country Monique was from in exchange for Monique being sent to America.