This.
That book talks about dealings just at the turn of the second era to the third (what with Tiber Septim and all).
I think borders can change a little bit in those several hundred years.
Actually, the book was written after the Oblivion Crisis, since it mentions the eruption of Red Mountain and the destruction of Vvardenfell on like the 3rd page.
If was saying that just the King was there and not the town, they didn't use proper grammar. Also, people in Falkreath say it's a relatively new settlement.