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.
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.
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.
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.
Never Bathe on Saturday - S4-E27
Continuity mistake: In the first scene, when Laura tells Millie she spent the whole day in the bathtub and Millie says "In a bathtub" Millie moves from sitting on a chair to sitting on the couch next to Laura in a flash.
Continuity mistake: The guy yelling about asking to see people that work in the office building in this episode gets told several times "no they aren't in". He sprints away from the desk with briefcase in hand, he's past Rob on the other side of the room. When they cut back to the lady you still see the guy's music transcripts and his brief case on the lady's desk still in his hand. (00:21:17)
The Ghost of A. Chantz - S4-E3
Continuity mistake: When Rob and Buddy are talking after arriving at the cabin and discussing the lack of wood that should be there for 3 years, a white birch like log on the very top of the pile inside the fireplace. The camera cuts to Buddy saying something about the ghost burning it, and when the camera cuts back to Rob the white birch like log is missing from the fireplace. Then when we see Rob making the pull out bed the log reappears back on top of the wood pile in the fireplace.
Continuity mistake: Rob is in the garage on his motorcycle. We notice the door to the garage leads out to the back/side yard towards the house, but in "Long Night's Journey into Day" the door to the garage is connected to the house from the kitchen.
A Vigilante Ripped My Sports Coat - S4-E5
Continuity mistake: Right before Rob starts the story to Sally and Buddy about how Jerry ripped Rob's sports coat, the box is on the floor. When we cut back to Rob, Buddy and Sally later on. The box isn't even in the room anymore. Then later on when Mel comes to pick up the box, it's back on the floor again.
Continuity mistake: When we first see Richie at the beginning of the episode he has extremely dark "bruises" all over his hands, arms and face. But by the end of this episode all the bruises are gone except for 1 which is on his face below his left eye (on our right). Bruises do not just vanish in 2 or 3 days if they are that bad.
Continuity mistake: In this episode we do not see a garage door. Yet in the "Long Night's Journey into Day" episode the garage door would have been right where all the tools and junk were on Rob's right (close to where Richie was standing talking to Rob).
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.