Where There's a Will There's No Way - S1-E7
Revealing mistake: When Grace slams into the side of the elevator buttons, they all light up except 4 (which is supposed to happen), but 5 lights up after she moves away from the panel. (01:22:30)
Alley Cats - S1-E21
Revealing mistake: When Will goes to pour himself a glass of whiskey, the brown liquid that is chosen to represent the liquor has foam bubbles on the top of it that resemble the ones that soda has.
Revealing mistake: When Grace is getting out the Board Games for her and Karen to play, the names of the Board Games have been covered with strips of tape. (00:53:00)
Revealing mistake: When Grace and Will are looking at the large tin of Protein shake powder, you can see there is tape covering all of the logos and brand name on the tin. (00:21:45)