When Thomas is saying goodbye to everybody, he says goodbye to George and after he puts him down, Sybbie hugs him. This was not scripted, Fifi Hart who played Sybbie did that. The look of surprise on Robert James Collier's face was real since he wasn't expecting that.
Carson becomes afflicted with a mysterious, incurable condition, the same condition his own father and grandfather had, which is the catalyst of the end of his career as Head Butler. Julian Fellowes has the exact same condition, a type of neurological disorder, that causes involuntary and rhythmic shaking, as Carson. Fellowes' own father had the exact same condition too, being diagnosed at 80, whilst Julian was 66 when he got diagnosed.
This final episode ends on New Year's Day 1926.
The series went out on a high, beating EastEnders and Strictly Come Dancing to give ITV its first Christmas Day ratings number one for 15 years.
The ITV drama was seen by an audience of 6.9 million viewers on Christmas night with the viewing figure peaking at 7.4m.
The man who played Bertie's best man when he and Edith get married was actually Harry Hadden-Paton's best man when he married his wife Rebecca Night.