4 Years, 6 Months, 2 Days - S5-E1
Continuity mistake: When Hailey finds Nathan asleep on the couch and cleans up his mess she originally has 2 beers and a bottle of tequila, but in the next shot she has beer, tequila and chips.
Please, Please, Please Let Me Get What I Want - S5-E8
Continuity mistake: When nanny Carrie is hungover and talking to Nathan she has a pot of coffee which changes volume throughout the scene, from almost full to almost empty to half full again.
Continuity mistake: Nathan is watching Haley walk down the aisle, but when the camera pans to Nathan for a face shot, it is Lindsey's head that goes past the camera, and Lindsey he is looking at. (00:18:50)