It May Look Like a Walnut! - S2-E20
Character mistake: Rob is having a nightmare, part of which involves the disappearance of his thumbs. When he finds Laura at home, the script calls for him to say, "I want you to help me get my thumbs back," but he actually says, "I want you to help me get my thumb backs." His thumbs are also still there but hidden (you can see a portion of them in one frame of the episode).
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.
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.
Plot hole: Sally Rogers appears on the Stevie Parsons show which is a late night talk show, the next morning she receives letters from as far away as Hawaii... the US mail isn't that fast.
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)
Character mistake: When Sally asks if Rob would give his party guests malaria, Rob responds later on with, "Oh, Roe, I would never suspect you!" Roe was Rosemarie's nickname on set.
Other mistake: When Rob dials the radio station, he dials the phone number and then looks it up in the phone book. He covers for himself, and then has a hard time keeping a straight face afterwards.
Suggested correction: The part is Rob checking to see if he had the right number.
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.
Never Bathe on Saturday - S4-E27
Continuity mistake: The bathroom door that Rob shot the knob off with the gun is not there in 1 scene, but suddenly reappears a little bit later back on the door, he's able to open and close the door with ease when he is in the bathroom with Laura while she's getting out of the tub. (00:20:30 - 00:22:00)
Your Home Sweet Home is My Home Sweet Home - S4-E25
Continuity mistake: In this episode it is shown that the Petries live in a house with a huge rock in the basement. In the episode where Buddy's brother, Blacky visits "Hustling the Hustler", they play pool in the basement and there is no rock.
Suggested correction: No, the Petries buy the house with the rock, but swap it with their best friends and buy the house next door. Therefore Jerry and Millie have the rock in the basement.
Rob has to pay half the cost for Jerry to seal his basement every year. The reason why is because Rob's rock redirects water that ends up flooding Jerry's basement.
The Petries did buy the house with the rock. At the end of the episode Rob explains how their rock caused flooding in the Helper's basement.
Continuity mistake: When Laura tries to read the phone number that Rob scratched out, Rob gives her the number as "New Rochelle 69970," which happens to be the Petrie's own phone number, as noted in other episodes.
Oh How We Met the Night That We Danced - S1-E5
Other mistake: When Rob is dancing with Laura and is supposed to step on her foot, his foot lands so far away from hers, it doesn't even appear that he stepped on it.
The Death of the Party - S4-E13
Continuity mistake: When Laura puts the ice cream in the freezer, the freezer is full, however when Millie brings over the ice they are able to put it in the nearly empty freezer.
The Case of the Pillow - S4-E21
Continuity mistake: In some of the courtroom scenes you can see feathers flying around, before Rob spills feathers all over the courtroom.
To Tell or Not to Tell - S1-E8
Continuity mistake: In this episode Sally asks Rob if he has a brother, Rob says "Yes, but he is married." However his brother Stacy is trying to become engaged later in the series, in episodes "Stacy Petrie Part 1 and 2."
Romances, Roses, and Rye Bread - S4-E7
Continuity mistake: When Sally lets Burt into her apartment, her hand is on her forehead and then all of a sudden it's down by her side.
The Ghost of A. Chantz - S4-E3
Factual error: When Laura and Sally are about to go to the bedroom, Buddy and Rob are going to sleep in the living room of the haunted cabin. Rob and Laura tell Buddy and Sally things like how he steals the pillow and he takes all the covers at home. However at home, they sleep in twin beds so they shouldn't know such things. However, they do have a son. They had to share a bed at least once in their marriage.
Suggested correction: Or they sleep in twin beds because he steals the pillow and takes the covers when they tried sharing a double bed.
It's not true that Rob steals pillows... Because every episode Rob has only 2 pillows. Unless he steals them in the middle of the commercials... and then they vanish before the next scene.
Revealing mistake: When Rob is talking on the radio, and says something along the lines of WOFF the station with (then a long pause while he plays a car sound) drive. The On the Air sign goes off before he says drive. He was still on the air.
Revealing mistake: Rob and Laura are both freaking out and panicking in their bedroom when all of a sudden Jerry shows up outside their closed window. Yet Jerry puts his arms in their room, showing it's not an actual window.
Continuity mistake: Rob, Laura, Buddy and Blacky are in Robs basement, there is no wine bar, or giant boulder, and the steps that come down from upstairs lead straight up to nowhere. Because there's a window to the left beside the steps, rather than how it was when they were buying the house where you could see into the house. And there's a giant gap under the wall behind the pool table. There's also a random door that leads somewhere also behind the pool table. (00:24:47)
