Okay, so we seem to be in complete agreement about how the math works out. If so, then I'm confused as to why you object so strongly to the prosecution's argument on purely mathematical grounds; I haven't read their argument myself, so it's entirely possible that the argument itself is weak in some way, but I think that right now we're just talking about the math.

If I may presume to diagnose your confusion, it seems that you're compartmentalizing between "mathematical" aspects of an argument and "other" aspects. But I'm not. I'm taking it for granted that "the math" is the argument. Probability theory is a mathematical formalization of the process of argument and inference. It isn't just a cool gadget that one throws in on special occasions.

So, I don't object to Massei and Cristiani's argument on "purely mathematical grounds". I simply object to it, period -- and in this post I have used mathematical language to describe, in precise terms, what my objection is.

(And I expected readers to assume, given my previous writing on the case, that this particular point was far from my only objection to Massei and Cristiani's 427-page argument that Knox and Sollecito killed Kercher; hence I was not expecting replies of the form "well, but they might have other good evidence that Knox and Sollecito are guilty". They don't; we've already covered that.)