Continuity mistake: From the outside of the house, you can see the staircase and door are to the far left of the house. But from inside the house, you have a fireplace and the staircase to the right of the door. So you know it's not the same house they use in the show.
Continuity mistake: Whenever the characters in this sitcom fall through the roof, they end up on the living room floor. The house is a very conventional design with a second floor and an attic, so they should end up in the attic or on the second floor.
Continuity mistake: In an earlier episode, Steve told Carl that he has to take charter flights because he was banned from all commercial airlines. Yet, in this episode, he takes a commercial airline to Florida.
Continuity mistake: When the family arrives home from the bowling alley, it is dark and pouring rain. After the kids go to bed, Carl and Harriet go to the kitchen and talk. If you look out the windows, it's daylight.
Continuity mistake: When Eddie comes down the stairs to ask his father again about wanting new shoes, his father says no. Eddie goes back up the stairs. Next scene, Carl walks to the kitchen, and Eddie is sitting at the counter.
Continuity mistake: Steve buys the ring for Laura at the end of their class project, then sells it to Carl as a gift for Harriet. Then when he proposes to Laura he says it's the same ring from that day.
Carl, Eddie, and Steve are out ice fishing. At one point Carl falls through the "ice" and you can clearly see that the "ice" is made of some sort of styrofoam. It looks like the stuff used for packaging. The snow looks just as fake.