Build a Better Mousetrap - S2-E15
Continuity mistake: When Al hits his thumb with the hammer when trying to hit the mouse in the wall, he hits his left thumb. In the very next scene, Peggy is wrapping up his right thumb.
Continuity mistake: When Al comes home, he finds a written message from Peg saying that she, Kelly and Bud are at Marcy's house performing the Village People. However, Peggy couldn't have written the message because when they agreed to play the Village People, they went over to Marcy's immediately. (00:04:50 - 00:06:10)
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.
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.
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.
Can't Dance, Don't Ask Me (aka Kelly's Dance) - S3-E13
Continuity mistake: While Kelly is dancing with the guy at school, a nerd girl starts kissing on Bud and pushes him backwards. The very next second when the scene changes, Bud on the left side is back playing the record for the music without anyone around him.
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.
The House That Peg Lost - S3-E16
Plot hole: Marcy and Steve live on the left-hand side of Al and Peg yet when they come home and see their house is gone Peg is looking out the window in the front door saying they're looking at the hole now they're looking over here.
Other mistake: When at the gas station, they are out of gas. He doesn't put any gas in but later Peggy starts the car up and drives away.
Other mistake: Al's and Peggy's birthdates are around 1948/1950, respectively. Supposedly, Al married Peggy after she got pregnant the day of his 4 touchdowns in high school in 1966. How could Kelly have been born in 1971?
Other mistake: When Steve wants his money back, Al asks how much was Steve bragging about earlier ($5) he could take and make a fortune, instead of giving Steve $5 it's a $20 bill.
Continuity mistake: The stolen Dodge is a 1974 model. Peggy tells Kelly that she was conceived in it. However, the episode "Christmas" (Season 7, Episode 12) has a flashback to Christmas 1974, showing both Kelly and Bud. Kelly's height had been marked on a door since 1972.
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.
Revealing mistake: Peg is making Al a steak. Problem is the burner isn't even on.
Continuity mistake: The out of order sign on the toilet changes position between shots. It's level at first. Camera cuts to other men. When it cuts back to Al it is tilted. (00:18:18)
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.
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)
Visible crew/equipment: At the end of the episode you can actually see a crew member at the door waiting for his cue to throw the tumble weed through the door.
Continuity mistake: Kelly knocks the lampshade off the lamp. Next shot shows it put back on although no-one is around it.
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.
