Continuity mistake: The kitchen changes from episode to episode, when viewed from the living room. If the set is going to be used the full kitchen is visible when viewed. But if it is not being used, often the set is pushed closer together. This is most evident when an actor is coming out of the kitchen the stove and the attached cupboards are practically at the door, providing just a bit of space for the actor to stand before making their entrance. Other times a wall is simply pushed up beside the door with the kitchen wall paper on it to appear to have continuity. This is only seen when the shot allows the kitchen set to be obscured.
Character mistake: After Jack (who's hiding from Chrissy's mother) ducks behind the couch holding a mop, Chrissy's mother comes out of the bathroom (which from the camera angle shown is in a straight line facing the back of the couch where Jack is) and walks to the right and all the way around the couch and sees the mop behind the couch and picks it up without seeing Jack at all. From where the bathroom is, she would have just needed to walk straight for the mop and seen Jack (yet she missed him).
Continuity mistake: After Jack brings the puppy over to the girls, the box he brought the puppy in was placed on the back end of their couch. At one point, it is knocked over, and you can see it falling down to the floor (past Janet). In a few shots, it's back on the table, and none of the characters were in a position to pick it up to place it back there.
Continuity mistake: While Jack is talking to the police officer about the missing rent money, they are standing in front of the TV set and the front door is open. When it cuts back to Jack and the officer, over Jack's shoulder the front door is closed, but when the officer turns to leave the door is open again.
Continuity mistake: When Mr. Roper tries to explain to the girls and his wife what he was doing in Jack's bedroom, watch over Mr. Roper's left shoulder on the shelf. The number of yellow cans on the shelf keep alternating between one and two cans throughout several minutes. In addition, also notice the suitcase on the floor under the shelf as well. Whenever one yellow can is shown, the suitcase is by itself and whenever two yellow cans are shown, there is a square silver bag in front of the suitcase.
Revealing mistake: Once Jack arrives home from his first day, Janet follows shortly behind him with her arms full of groceries. She hands the bag to Chrissy but watch at the bottom of the bag - it starts to come apart and Chrissy grabs the bottom of it and holds it together. The end sight gag is that when Jack storms out, and Janet storms off, Chrissy then goes to go to the kitchen, and the groceries fall out of the bag at the bottom - but it's because then she's holding the bag then around the center.
Character mistake: At one point in this episode, Jack is chatting with Larry about the nude beach and in frustration says "all the best looking girls were wearing towels" right in front of Mr. Roper as well as showing interest in seeing Janet without her clothes also in front of Mr. Roper. Jack is supposed to pretend he's gay when Mr. Roper's around him. Roper luckily didn't pick up on it this one episode either time (rather showing concern for his wife).
Plot hole: Janet and Chrissy accuse Jack of making the fake BBQ telegram. However, Jack was at The Apartment the whole time, never left once until after he found out Lori was the one who made the telegram. If it was Jack who made the fake telegram, he would have had to leave The Apartment to do that.
Visible crew/equipment: In the episode "A Camping We Will Go", when Lana and Mr. Furley show up to the Cabin unexpectedly, watch closely when Lana tries to sit next to Jack on the couch.if you look through the window by the flag hanging on the wall you'll see Larry's girl, Laura, waiting outside by the front door (in her bright pink outfit) waiting to make her entrance.
Plot hole: Chrissy's policeman cousin informs the roommates that there was a complaint from a neighbor about her husband on his roof watching the girls dance in The Apartment with binoculars. However, when the girls were dancing, the front door was fully closed and the very thick drapes were fully closed so how could such a complaint exist?
Revealing mistake: In Angelino's kitchen, when Mr. Angelino comes in and mentions steaks for eight people are needed, look behind him at the door's window. Janet is briefly seen watching (as if waiting for her cue to enter), then quickly ducks out of sight. A second later, she's seen again while Angelino asks Felipe to help him in the freezer. She then runs in the door with Furley as if they first arrived at that moment.