The reason I write about this is because of an article I found which delves under the factual content of Michael Mann's The Insider. When The Insider was released as a dramatized version of events surrounding Jeffery Wigand, Lowell Bergman and Brown & Williamson it was immediately open to scrutiny, mainly from the real life characters the film served to depict. Wallace was particularly unhappy. All these criticisms have been openly reported and Mann has responded to them honestly and admirably.
However, the article I have found is useful as a way of understanding indirectly some of Michael Mann's approach to "truth" and his philosophy and purposes towards storytelling. Revisionist history is always never far away from film creation. Click here for the article, but a brief excerpt is below to set the scene.
 But then all of a sudden something even more astonishing occurred to me. Instead of objectively seeking out the truth behind The Insider like I had planned, I had fallen victim to the lure of Michael Mann's convincing enplotment! By immersing myself in the movie, I had unknowingly accepted Mann's filmic version of the truth. Because I formed an emotional attachment to the likable characters of Wigand and Bergman, I never once hesitated to believe their stories. Thankfully, extensive research forced me to be a more critical analyst, and I saw how Mann had twisted and manipulated various scenes and real-life characters to his advantage as a filmmaker."Michael Mann's The Insider - History Redefined." 123HelpMe.com. 23 Mar 2011