The Day Nothing Happened - S2-E20
Revealing mistake: The snowman is an obvious Styrofoam props the kids have set up in the family room, as the fake snowflakes fly right off it during the kids play, including the white patches beneath the body.
Family Affair (1966)
1 mistake in The Day Nothing Happened
Starring: Brian Keith, Anissa Jones, Johnny Whitaker, Kathy Garver
Trivia: In the season 5 episode "It Can't Be Five Years?" the woman playing Uncle Bill's secretary is Sebastian Cabot's daughter Annette.