A Filmmaker's Responsibility

Several of this year's Oscar contenders claim to be based on true stories, and they do say "based on." But, somehow, that phrase is usually ignored or forgotten, and a film's ~ or a book's ~ version of history ends up being the version people remember and cite as fact. Does a filmmaker bear any responsibility for that? As one can imagine, there are competing answers to that question (video): http://www.bbc.co.uk/news/entertainment-arts-21040913