I believe the 65 million is an undercount.
It is a massive, deliberate, propaganda-driven under-count!
The Soviet, alone, accounted for about 100-million during the purges of the 30's. Mao accounted for an additional 100-million or so during the 40;s and 50's.
Then throw in Cambodia, Ukraine, etc and, maybe, another 100-million can be accounted for.
Finally, the U.S. should be on this same list for the 100-million, or so, exterminated by the U.S. government since the 70's. (And continues even today...)