I don't believe that the native Americans died due to the disease - I do think they got infected, but I doubt they got entirely wiped out - wasn't there all that consistent annhiliation going on by the white settlers? Doesnt that count? Is the Mann hypothesis actually putting forward that all Indians are dead because they died of disease?

If so, *facepalm* It's on record that the whites systematically wiped out the Native Americans! And the Chinese/Asians who immigrated there.