Episode #5.6 - S5-E6
Continuity mistake: When Lady Mary is competing in the Point-to-Point horse race, she is riding her mount sidesaddle style, wearing a long-skirted riding habit. When she (actually the stunt rider) jumps a hedge, she is now riding astride, with both legs over the horse and using a two-stirrup saddle. Also regular riding breeches (pants) are underneath the long skirt when it flies up a bit. These would never be worn with this type of lady's riding habit.
Episode #5.7 - S5-E7
Revealing mistake: When Tom and Sibbie are on the bridge dropping sticks into the water, they run to the other side and you can see their movement through the bricks.
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.
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.
Answer: Yes, because at the time it was not sure if it would continue and since it was short it could be seen as a miniseries. it also depends on where the producers decide to submit it. However since it continues on it is no longer a miniseries but a full series and thus cannot be submitted in the miniseries category anymore.
luke f