Ha! I was testing you on that. Graham Hancock has distributed this comet theory much more widely. For your original authors of the 2006 book.
The idea that former civilizations (of some sort) were swallowed up when the glaciers melted and seas rose to current level, was not his either. He was still pushing the idea that the Ark of the Covenant was in Ethiopia back when I was already “SunkenCiv”. ;^)