And that's certainly a valid interpretation, but it is still an interpretation. (I feel like one of those "militant agnostic" bumper stickers--I don't know and you can't either! In all seriousness, though, I think this comes down to personal interpretation.)
I would certainly agree with this. I do think my point of view has been thoroughly coloured by the use of Barbara Kellerman as both characters in the BBC which I saw before reading the books (though I was only a few years old when I first saw them. As a result, my interpretation could conceivably have no basis but I feel there's enough evidence in the book to support it - thus I shall keep it.