I think you're using Google too robotically.
LOL! But Fagan's "15,000" reference there is alluding to the date of the climactic trends he's talking about, not to the rise of civilization. "Civilization" would be referring to walled settlements on the scale we find at places like Sumer, which Fagan wouldn't acknowledge as existing 15,000 years ago. Fagan is a pretty conventional archaeologist who spends a lot of his time defending the established consensus on the Bering Strait hypothesis, and as such he follows the established academic view on the date of the rise of civilization.