Personally I enjoy speculation to the point where it's about what a writer might have meant, but when it comes to stuff he couldn't possibly have known about, like this, then it loses me a bit I'm afraid, because that is unlikely to have been the author's intent. Horses for courses.
It's a bit like reading Romeo and Juliet and through comprehensive pharmaceutical knowledge identify the precise compound Juliet would have used to feign death, but seeing as that would have only been available in the Far East during that period of the Renaissance then Friar John must clearly have made a pilgrimage to the Orient at some point in his youth, where he would have discovered their techniques for... etc etc