Yes this is precisely my problem
He starts with the false assumption that "the only explanation is that the universe is created from nothing" and then uses some pseudo-mathematical mumbo-jumbo to try to justify this.
Would you rather prefer a universe that is created from something? If you do, you then have to face the infinite series of questions what created that, and what created that, ad infinitum
So a universe created from nothing as a reasonable assumption.
This is a view shared by many physicist including Lawrence Krauss