Continuity mistake: Marcy says her parents never let her have a Barbie as a child. In Season 2 episode 14, Guys and Dolls, Al and Steve steal Marcy's Barbie from the basement to sell to buy a new baseball card.
Other mistake: When the fat woman gives them the straws, there is no reason why one would already be cut short. They didn't cut the straw. How did they get a short straw?
And Bingo was Her Game-O - S9-E21
Factual error: The "Geo Metro" in which Peg and Marcy ride looks nothing like a Geo Metro.
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.
Requiem for a Dead Briard - S10-E3
Continuity mistake: When Peg is comforting Kelly about Buck passing away, she is holding a bag that says "Petropolitan" on the front. The next shot when they go back to her, all a sudden the words are gone from the bag she is holding and Bud is holding a bag with those words.
How Bleen was My Kelly - S10-E5
Continuity mistake: The family assumes Fox Viewing positions suggesting they are using an antenna to get reception. A few episodes earlier, Al changed their cable television channels to all men channels. You don't need antennae if you have cable.
Suggested correction: Cable and antenna isn't an either/or situation. You can have cable but still use an antenna to get a local channel if your cable provider doesn't offer that station.
Flight of the Bumblebee - S10-E7
Continuity mistake: Jefferson mentions having Thanksgiving dinner at Marcy's father's house. Yet, in the pilot, it's mentioned he's dead, as well as her two stepfathers.
Revealing mistake: When they blow up the scoreboard at first in slow motion, the entire scoreboard is blown up and destroyed. The next shot only a small portion at the top and middle is destroyed, not the entire thing.
I Can't Believe It's Butter - S10-E13
Revealing mistake: When Griff drinks the gravy right before calling "Butter", his glass is empty.
I Can't Believe It's Butter - S10-E13
Plot hole: Griff doesn't know Peg's mom is Butter. He comes to Al's wanting to meet her. Al gathers the family to talk about what to do. They say Griff can't know its Peg's mom, yet they talk out loud and Griff is standing right there while they are sitting at the kitchen table. It's not until the end of the episode he finds out.
The Hood, the Bud and the Kelly (2) - S10-E15
Revealing mistake: Whenever Al or Jefferson falls off the roof you can plainly see it's a dummy wearing their outfits.
Character mistake: When Bud is showing Al his school project of a fan page turner, he has it on the left side and blowing the pages left to right. That would be blowing the pages the wrong direction to flip pages. It should be on the right side changing pages right to left.
Continuity mistake: Al enters the house at 3am with Lucky. It is sleeting outside and there is snow all over the front and backyard. Later that day, Al is in the backyard, no snow to be seen, and grass and bushes in full bloom.
Continuity mistake: In this episode Al is building a dog house for Lucky. In Season 9 episode User Friendly, we are shown that there already is a dog house, which has electricity and a light.
Factual error: Griff's shown being strapped into the electric chair. Problem is Illinois had stopped using the electric chair and switched over to lethal injection in 1983.
Visible crew/equipment: When Marcy announces they only have time to grab their most precious personal possessions Kelly notes her own, and in the next shot the boom mic makes a happy appearance at the top of the screen. (00:07:45)
Visible crew/equipment: When Al and Jefferson are knocking down the door with Bud, the shadow of the camera is visible on the wall for a second or two.
Breaking up is Easy to Do (2) - S11-E15
Continuity mistake: Before the dinner date, Peggy takes a plate of raw meat out of the dishwasher. Bud and Kelly go to help her put it on the stove, but Peggy's plate is now empty and the meat is on another plate already on the stove. Yet strangely, Bud and Kelly take the empty plate from her anyway and put it on the stove next to the other one.
Breaking up is Easy to Do (2) - S11-E15
Revealing mistake: When Al falls on the bed with the shoe and puts the hole in the water bed, the shoe doesn't hit the bed anywhere near where the water starts to shoot out from.
Continuity mistake: In one of the scenes where Bud is forcing Kelly to eat, he tries to feed her cheese whiz but she resists and some of it gets on the side of her mouth. In the very next shot, when Peg runs in, the cheese is no longer on the side of Kelly's mouth.