Continuity mistake: In the final scene of the episode Brooke joins Mouth at the side of the Rivercourt, but when the camera switches to further away it shows Brooke walking towards Mouth and joining him again.
When It Isn't Like It Should Be - S3-E18
Continuity mistake: Nate touches a photo on the wall of a smiling late Keith, with Lucas as a small boy. Next shot, Lucas taps on the door to let Karen know the gang is taking off, but there's no response. Next shot shows Karen sitting the other side of the door, grieving, holding that same photo of Keith and Lucas. (00:02:45)