Continuity mistake: The cigarette lighter Robinson uses to set the incriminating papers alight disappears from the desk as he makes his phone call. (00:21:30)
Too Many Christmas Trees - S4-E13
Continuity mistake: When Steed and Emma are driving to the estate, the car's windscreen keeps disappearing. It's there in full shots, gone in close-ups, and reappears again every time we cut back to a long shot. (00:10:30)