Episode #6.7 - S6-E7
Continuity mistake: When Edith stops by her office Laura's there and she's holding a cigarette, which keeps switching between her left and right hands while the two women talk.
Episode #6.3 - S6-E3
Factual error: During the wedding the groom and ushers are wearing boutonnieres pinned to their labels. Pinning boutonnieres to your lapel is a very new method. Traditionally the flower goes through the lapel button hole. This would still be a common use for the button hole at the time.
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 ★