As a friendly advice I would suggest refraining from using the term "proof" in any kind of metaphysical debate. The topic is beyond the realm of scientific logic, and claiming to have proven anything tends to provoke counter-arguments that deals primarily with alternate views rather than elaboration on the original one.
I think this is extremely relevant. The term "proof" these days has aassumed the connotation of scientific proof. There is of course a difference, and a big one at that, between modern scientific proof and experiential proof. I think that both can be logical, indeed both have to be logical. Proving to oneself is easier than proving to others however, and more often than not the latter is a thankless and fruitless task. Better perhaps to put one's energies into the former. How does one do this? Well, this is a work of ages. Amongst Buddha's last words were "work out your own salvation". The Buddhist way is to trust in the Buddha nature; simply put "buddhi" or intuition, something we all can and should do rather than pay heed to so many proclamations of truth and proof.
As an aside, one very appealing thing to me about Graham Hancock is that he has never, as far as I know, said that he has proof. He states his findings in a passionate way, and presents compelling arguments yes, but not as dogma as so many of his peers and establishment academics do. He uses the word "may" a lot.