I am not sure what I had in mind when I had written the reply, but I guess it was somehow related to existence of more than thousand mutually exclusive hypotheses supposing destruction of the Earth, each of which should, if given reasoning is correct, have probability 1/1000 or more.

If you have a hard time finding a theory that you can't, by this criterion, say is true with more than 999/1000 probability, I'd say that's a feature, not a bug.

Full complex theory, maybe, but there should be plenty of hypotheses similar to "the Earth will not be destroyed by LHC" with far greater certainty than 0.999. What about "the sun will rise tomorrow"?