Continuity mistake: When Cindy goes downstairs to ask "isn't anyone coming up to say goodnight?" or something similar, when Alice is talking to Mike and Carol about Sam not coming over, Cindy is wearing her pyjamas. She then gets in trouble and goes straight back up to her room and she is suddenly dressed in jeans and a top - her hair has different hair ties in it too.
Continuity mistake: When Jan comes home and tells her parents that Clark didn't notice her at school, she's wearing a white blouse with a floral design and a red ribbon in her hair, but when she gets to her bedroom and accuses Marcia, she's wearing a striped blouse and a light green hair ribbon. Then when Jan talks to Greg she's wearing a green tee shirt and a dark green ribbon, but when she asks permission to go to the store she's back in the striped blouse and light green ribbon.Super Grover
Continuity mistake: When the vase gets broken, it's easy to see that one large piece flies off the chest of drawers onto the floor. And when the boys look down at the broken vase from upstairs, three pieces are on top of the chest of drawers. But Greg - seen later trying to fix it - says something to the effect of "Good thing it only broke into three pieces." So what about the piece that flew off onto the floor? (00:02:00)Jeff Swanson
Revealing mistake: One of the times that Sam comes over to visit Mr. Brady, he comes in through the back sliding "glass" door. There is no glass in the door. You can tell this because when Sam closes the door, to do so, he puts his hand through the areas where glass would be.
Deliberate mistake: When Bobby's at the treehouse the second time for his initiation into the club, there's a boy already up in the treehouse, and after Peter takes the birdcage from Bobby's hand, the next closeup of the boy in the treehouse is a flipped shot, note the wood boards. (00:08:25)Super Grover