Board Thread:Episode Discussion/@comment-14138255-20170108170343/@comment-26018514-20170121060134

I'm pretty sure it was either in commentaries when Sun was on screen, Or on a bts extra on the Dvds, or in a stream from a QA when Monty was alive(I recall he was in the room and a writer said it, but not which of the 3), and I'm pretty sure it was also mentioned after Monty's death in another extra/QA/Panel, but I can't narrow it down farther and don't feel like looking it up atm.