Revealing mistake: In the scene in the kitchen, Lucille Bluth takes a bottle of "Bushmills" (a brand or Irish whiskey) out of a grocery bag during a scene in the episode; however the liquid inside is clear/transparent and obviously not whiskey.
Continuity mistake: At the restaurant, as Lucille is saying "I've been a horrible mother", her hand goes from the base of her wine glass to holding the top of it, instantly between shots.
Continuity mistake: In the opening scene when Lucille is unloading groceries, the paper bag on the table keeps changing from being crumpled to smooth.
Continuity mistake: When Lindsay first visits George Senior in prison, she is wearing a hat. From some angles only one ringlet of hair is sticking out of the hat, but from other angles there are several pieces sticking out.
Continuity mistake: In the very first scene with Lucille and Michael talking in the kitchen, Lucille is at the cupboard packing away groceries. The shot cuts and she is instantly back at the kitchen counter.
Continuity mistake: When Michael is lying on the couch at his mother's apartment, the blanket covering him hangs over the side of the couch in some shots, but from other angles does not.
Continuity mistake: When Michael, Gob and Lindsay are in the kitchen talking about throwing a surprise party for their mother, Michael puts down a can of Sprite on the counter in front of his bag. In the next shot, the can is next to the bag and the coat that was over the bag has also moved, without there being time for anyone to move these items.
Chosen answer: "The One Where They Build a House," S2E2.