So, is he saying that in the background, there was dialog to this effect? If so, maybe somebody that DVR'd it and still has it can have a listen. I don't recall that, but then I only watched it twice.
Douglas was either confused about what ended up in 4x12 (4x10) "Revelations", and what was edited out to 4x13 (4x11) "Sometimes a great notion", or pretended to be confused to be able to give away spoilers in a casual way.
This dialogue and so on was shot together with "Revelations" (of which "sometimes a great notion" is basically part 2 of 2), but it is yet to be broadcast.
For those who doubt his words, see more info here: http://syfyportal.com/news425407.html
So, even more spoilers there. And what Douglas said - it's very likely to be true, perhaps said in a bit confusing manner, but true.
I have no idea how it it possible that the colonials don't know what is in their own scriptures, wonder how they will explain that one, but this particular tidbit was already leaked way earlier by the "ask Ausiello" column, and there is no indication that info also came from Douglas, at the time.