I really enjoy it but one episode troubled me. It's the one set in the summer fair where they are judging the flowers.

The dowager countess (played by the inimitable Maggie Smith) has her roses ready to win. She always wins because she's the countess but awards the prize to a lowly serf after some criticism.

This is a direct copy of the same scenario in William Wyler's Mrs Miniver (1942).

Was the Downton Abbey writer paying homage, was he copying directly or was it a buried memory that he thought was original?

I suppose the only way to know is to ask him.