Episode #3.3 - S3-E3
Other mistake: At the end of this episode after Edith is jilted at the altar, Albert makes some rather "home boy" comments about the food and then asks if there is any cheese to eat as if that's all he's used to or wants. This seems inconsistent since for the rest of the series Albert is the guy who seems to appreciate well-made food and wants to be a cook.
Episode #3.6 - S3-E6
Factual error: Thomas Barrow lights a cigarette with a disposable lighter which were not invented until the early 60's.
Christmas Special 2012 - S3-E9
Continuity mistake: In this episode, Cora tells Mr. Gregson that she started reading "The Sketch" when Edith began to write for him. In Season one, episode one, Carson tells William to iron "The Sketch", because "her ladyship only ever reads the Sketch."
Answer: Word gets around. The staff are gossips amongst themselves, but those loyal to the family know who to keep secrets from and who they can trust to share in the knowledge.
Phixius ★