[lagadu]

I believe you're in error with the assumption that "there are countless universes" means multiverse in his description. It means that there are countless universe possibilities we can imagine, one for each permutation of the universal constants. Other than a small subset of them, one of which we exist in, nearly all of them would not be able to contain life because they wouldn't have conditions to do so. It doesn't imply that these other universes exist in some "physical" sense, only conceptual.