Starring: Dick Van Dyke, Mary Tyler Moore, Morey Amsterdam, Larry Mathews, Rose Marie
A Man's Teeth Are Not His Own - S2-E13
Revealing mistake: When Rob is "playing" the piano none of the keys on the piano look to actually be pushed down. Also when he's scratching his back with each of his hands the notes on that same side of the piano are still played. He's not actually playing the piano. (Except for the last 2 notes or chords). (00:02:46 - 00:03:27)
Your Home Sweet Home is My Home Sweet Home - S4-E25
Continuity mistake: The Petrie house (where Rob and Laura, Jerry and Millie are standing together bickering) is completely different from the episode "Where Did I Come From?" and a few others.
Rob Petrie: At least I'll prove one thing tonight: Television writers marry the prettiest girls.
Trivia: During the fourth season, actress Rose Marie suffered the tragic loss of her husband to whom she had been married for 20 years. Amidst her mourning, Marie felt that the grief and pain of loss was too much to bear and wanted to leave the show entirely, just before the fifth and final season. John Rich, one of the show's directors, was there to console her and convince her to come back and finish out the remainder of the show.