Springtime - S3-E2
Continuity mistake: While Adam and Ted Hackett are talking on the front porch, in the exterior shot we can see the tablecloth inside the house is solid white, but in the interior shots the tablecloth has a red/white check type pattern. (00:31:15)
Continuity mistake: After he's dragged behind the horse, MacKenzie's facial abrasions keep changing completely from one scene to the next. And one day later, they've miraculously healed enough to be covered by one little bandage.