WI: Evidence of the Cambodian Genocide mostly destroyed?

[Kubo Caskett]

Nothing hurts the cause of an evil regime like the truth and it sure did hurt the warped cause of the Khmer Rogue and rightfully so when evidence of their antics came out when the war between Cambodia and Vietnam happened. But of course there always had to be apologists and deniers regarding terrible atrocities and the Cambodian Genocide is no exception, except its a completely fringe thing given the massive amount of evidence that well destroyed the denial movement.

Now with a POD no sooner than 1970, is there a possible way to destroy the evidence in that it would enable the denial movement much longer than it had IOTL?

[orvillethird]

Well, have the US and UK (who, oddly, backed the Khmer Rouge) try and deny the claims of things. Getting rid of John Pilger would do much the same (and enable further abuses of power).