Yes, I suppose I may have taken a bit of liberty with the term 'historian'. That comment was a bit clumsy, my aim was just to say his idea isn't without linguistic and historical justification, though should not be interpreted as 'ascertainable fact', as you say to attempt a rephrasing. I was attempting to get this idea across without repeating all the justifications he used, and came up a bit short as you are right to point out.