This is not something unique to Russians. I bet almost all aggressors and genocidal maniacs have at some point reacted in such a way and denied or minimized their atrocities, or even claimed they were never committed.

For example, after the Bosnian genocide in the 1990s, when it was shown that a staggering 8,000 Muslims had been massacred in a matter of several days, the Serbian president Slobodan Milosevic first denied that any war crimes had taken place, and then justified it by claiming that all the victims were Bosnian army forces and they were all killed in a firefight.

Likewise, when the Rohingya have been massacred by the Burmese military, the Burmese president, Aung San Suu Kyi, dismissed these crimes as "fake news" and said the Rohingyas were attacking themselves.

These examples could go on for pages, but the point is, in every instance when independent investigators finally do investigate these crimes and documents them, the aggressor and their enablers denounce the proceedings as "fake," or claim they never occurred.