Lots of interesting points here... But my title states "holes" in this theory, which implies that I question the validity of this theory with missing evidence, such as human traces of this supposed "ancient civilization".

Someone brought up the question about the real age of the pyramids, and that was going to to be my next topic... Because if they were built by these ancestors or survivors of this ancient but advanced civilization, and we say that they they were exterminated by this cataclysmic event that supposedly happened over 10K years ago, then that means these pyramids must be a lot older than 4500 (by Egyptology account), or 500 years (by Mayan account). Then we really don't know how old the other cyclopean sites really are (the stone henges, the Tiwanaku etc).