Episode #1.1 - S1-E1
Continuity mistake: Near the end of the first episode, when Robert Crawley gets into bed he first puts his candlestick down on the nightstand. Then it disappears. Then when he's in bed and ready to blow out the candle, it's suddenly back again.
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