These types of posts are .. well thought-out, and usually posted by someone with relevant education. But they are not reviewed documents or journal articles, and you can _tell_ when someone is mixing in a lot of their own educated guessing with the research they've done. Which is the case here.
He probably wasn't intending it to be taken as authoritative source, but that's how most people will _read_ something like this after running into it on the front page of HN. And most of this is just.. guesswork.
The author is presenting a plausible enough theory without any evidence that it is actually more accurate than the actual historical texts.
As one example, the author goes on and on about the importance of the conduits into London - but here's how actual documents from the time describe them:
"A certain conduit was built in the midst of the City of London, so that the rich and middling persons therein might there have water for preparing their food, and the poor for their drink"
He probably wasn't intending it to be taken as authoritative source, but that's how most people will _read_ something like this after running into it on the front page of HN. And most of this is just.. guesswork.