History is the study of past events, not the events themselves. So, over time, as the body of knowledge, and various interpretations arise, the historical take on events changes. This isn't revisionist history, it the process of the academic discipline of history.
Then you have people who write and publish "history" books that ignore or distort data to present a picture that fits, not the facts, but what they want People to think about the facts.
Here's an example: After the Reich, The brutal history of the Allied Occupation. (Giles MacDonogh. 2007, Basic Books, New York, NY).
This is all I will say about it: Between pages 298 and 299, there are photos. One of these photos is presented as that of "...a drunken American officer sleeps through a striptease in his Darmstadt mess in April of 1948". This is very problematical. One, the man isn't in uniform, and in 1948 American troops were required to be in uniform virtually at all times. Certainly in the mess. Two, If you've spent much time in Europe you know that Europeans and Americans don't have the same body language. This guy was a European. Three, he didn't have military hair cut--I have seen enough of the grooming standards to know that it wasn't a military haircut in 1948, either.
And, of course, sleeping through a striptease is such an act of brutality.