The Brave and the Backache - S3-E19
Other mistake: When Rob goes into the office of Dr. Philip Nevins there's smoke rising from the ash tray on his desk. Throughout the scene nobody's smoking.

Starring: Dick Van Dyke, Mary Tyler Moore, Morey Amsterdam, Larry Mathews, Rose Marie
The Brave and the Backache - S3-E19
Other mistake: When Rob goes into the office of Dr. Philip Nevins there's smoke rising from the ash tray on his desk. Throughout the scene nobody's smoking.
Sally and the Lab Technician - S1-E3
Continuity mistake: When Jamie Farr the "Snappy Service" guy comes in and gives everyone their coffee Buddy throws a straw into the straw cup, but it falls down on the floor then vanishes, never to be seen again.
Laura Petrie: You wanna end up another Dwight Heatherton, go ahead.
Rob Petrie: Who's that?
Laura Petrie: Dwight Heatheron happens to be an excellent writer who is unknown because he gets no publicity.
Rob Petrie: Then how do you know him?
Laura Petrie: Oh Rob, he's famous.
Harrison B. Harding of Camp Crowder, Mo. - S1-E6
Trivia: Rob tells the police over the phone "Get a prowl car to 148 Bonny Medow Road." 148 was also Dick Van Dyke's weight during the TV series.