Buddy Sorrell, Man and Boy - S5-E22
Other mistake: Rob got a new watch for his birthday a few seasons back. Yet he's still wearing his old watch. And also his watch time says it's 3:00. Rob and Sally would still be at work if it was actually 3:00.
The Dick Van Dyke Show (1961)
1 mistake in Buddy Sorrell, Man and Boy - chronological order
Starring: Dick Van Dyke, Mary Tyler Moore, Morey Amsterdam, Larry Mathews, Rose Marie
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.