When we're told we have to observe certain hard, fast lines, we're being shunted into a way of apprehending the world. I try to stay conscious of what's arbitrary or self-interested in the lines other people draw. I'm making the argument that these lines are always problematic, subjective. We make political choices as well as formal choices when we call our writing fiction or nonfiction. Why should I allow someone to sneak in a political agenda when they insist on distinctions between fiction and nonfiction that I don't believe really matter.
All forms require choices.
To answer that question, I have to look back at 30 years of writing, and my writing has changed, I hope, during that period. My opinions have changed as much as my approach to writing has evolved. I carried the interviews away in my head and wrote them down, sometimes a week later, and checked them with my brother, got the substance right to his understanding and mine, but I'm responsible, reader, for the words on the page. If the reader is given this kind of info, we're in good shape. I'm not a writer who has ever sold enormous numbers of books.