A Marxist magazine once claimed journalists had falsely alleged they'd seen people starving in a Serbian concentration camp during the Yugoslav war, by using a misleading photograph. Here, one of the journalists tries to defend himself, using the emotional tricks perfected by professional survivors of another massacre:

"What most concerns me is the searing pain the denial of the camps causes to the survivors of the bloodletting, and to the bereaved, with many of whom I have remained in touch since 1992."

http://www.guardian.co.uk/world/2010/mar/01/radovan-karadzic-bosnia-war-crimes-the-hague

I am not denying these atrocities happened - I am simply defending the presumption of innocence for those alleged to have committed them. But merely saying you believe something happened is not enough to protect you from the charge of 'denying' it. You have to believe every detail, and throw in a load of emotionally-charged political propaganda for the powers-that-be.