Visible crew/equipment: When Grace has stopped and is trying to fix her bike, a red car passes her, splashing up mud all over her. As the car passes the camera, the whole crew and equipment is clearly reflected in the side.
Continuity mistake: When Leo comes into the apartment and starts talking to Will and Grace, they're sitting at the table. Grace has a newspaper which she holds over her plate. Between shots the newspaper keeps vanishing then reappearing.
Continuity mistake: When Will and Grace are on the biking trip with Leo, going to pick a pumpkin, during Will and Grace's conversation the scenery and background behind and around them keep alternating and changing between shots.