Marcelo's Reading and Thinking Log

I was reading an interview with historian Carlo Ginzburg the other day and he quoted Henry James on how novelists had a complementary role relative to historians, in documenting a certain period. A few days later, I began musing about historic fiction. It became clear to me that the aforementioned quote wouldn't apply to that particular genre, or rather, it would, if you consider that the work is actually, somehow, about the period in which the work was written. I will not justify my assertion, but I will give an example that may or may not make things clearer. My example is Vincent Van Gogh. There was a common belief that he cut his own ear off, out of, it appears, some sort of mental condition which he allegedly had. Recently there was a research (sorry, no references) that came to the conclusion that this never happened, and what evidence there was pointed to a different cause to his missing ear, namely, he had a fight with Paul Gauguin and in that fight Gauguin cut Van Gogh's ear off. Now, I am familiar with two works of fiction about Van Gogh, the French movie by Maurice Pialat and the American movie adapted from the novel by Irving Stone. In both of them, he cut his own ear off (I have also seen another film named Vincent & Theo, but I can't recall whether this event is depicted in it). I am willing to bet that all other available fiction about him follows the once widely accepted - and now disputed - version of the events. My question is: considering how fictional biographies of real persons are notorious for the liberties they take regarding those persons' real lives, why hasn't anybody decided to take a liberty regarding that particular event which would unwittingly be truer to what really happened? What was so compelling about the earlier version? I always accepted it because I always assumed that it was based on some kind of evidence. The people who write books and make films don't have that excuse, since they are supposed to do some research about the subject they are dealing with. Anyway, there's my two bits. And I have my own theories about the answer too, but I won't reveal them unless under torture.