Yeah, I have to go against Dawkins here. What if they were a monoculture? A monoculture that had a religion that was pro science? They could be pro science, but have no version of Occam's razor and thus leap frog traditional rules of logic.
Or their relgion could be some sort of ancestor worship. Or be a cargo cult that has otherwise 1950s technology, but copies of a FTL drive that they otherwise have no understanding of. Or one the was once presided over by a Q like being who eventually got bored and left.
I can imagine numerous scenarios that would involve religious FTL aliens. His statement seems more likely, but not exceedingly so.