Plot hole: In the episode "That's my Boy" when they bring Richie home from the hospital, Rob and Laura are living in the new house they have. However, in the episode "Where did I come from" when Laura went in to labor, they lived in a different house. They couldn't have moved while Laura was in the hospital.
Other mistake: Mainly in "Who Stole My Watch?" and 2 other episodes the the Petries and the Helpers talk about the Helpers dog, but there is no dog, the dog doesn't have a name they keep saying "our dog" or "their dog", and there's no dog house, water bowl or food bowls for a dog at their house in any episode.
Other mistake: Any time Rob has to go to a doctor or to Jerry to get his teeth worked on, if you look at the window behind him and whoever is working on him. It's the same buildings every time. Even though he goes to different doctors. Also, that window and the curtains are also the same exact windows and curtains in Robs office.
Factual error: Rob mentions several times "I broke my cheek" if he actually broke his cheek we could see a spot there, either a divot in his face where the accident happened and was not fixed, or we would see a indent line from where they put stitches on his face. We see neither of these.
Continuity mistake: In the 1st episode there are about 20 pictures behind the writers desk. Next episode... Gone, replaced with a giant bookshelf and a bunch of scripts. The bookshelf was behind the couch in the 1st episode.
Continuity mistake: The whole kitchen is completely different from episode 2 onward till the end of the series. (Episode 2 onward it looks the same except for the outside behind the sliding glass door but the background is also flat. The house(s) and trees are flat, there are also no birds out there making any noise).
Continuity mistake: In "Sick boy and the Sitter" the door to the writers room says "Allen Brady Show WRITING STAFF" in a nice 3D all bold caps type font (except for the 1st "N"). In this episode the door then says "Alan Beady Show STAFF WRITERS" also all caps, not bold, and not 3D type font.
Factual error: This is the only episode that Harrison is seen, mentioned or even talked about. But in all the rest of this series there is no Harrison. Both Harrison and Rob mention that he was the guy on the spot light fir the shows... But not one time did we see a spotlight on Rob in any of the episodes.