Just look at Royal massacre. Dipendra has been made liable of the killings of his parents and siblings even though normal people in Nepal don't by that today..500 years from now..I think everyone will buy that Dipendra killed everyone. He may have killed but there was no independent investigation. 

So, 1000 years from now..someone like the professor here will use the current information as fact. I've read somewhere that 30 thousand years ago, the sewage system in the Indus valley was more modern than what it is today in current day Pakistan. How such knowledge could disappear. I guess smart dudes will always be smart and there's nothing wrong with that. Survival of the cunningest species rather than fittest species.