Interesting. I have read that book, though not recently. I did not like it much, and I definitely got a Capote-esque sense that O'Brien didn't care much to relate what actually happened. In fact, as you quote, he explicitly recused himself from the truth before things really got started. I think the main reason I didn't like TTTC was the style, though, since I don't really have a problem with depicting events through slightly sensationalized fiction. TTTC indulged in a sort of mystical realism of Vietnam, as I recall, which struck me as appropriate; Capote in In Cold Blood and this other thing presented fiction as fact to an unknown extent. We were left having to trust him, and he was notoriously untrustworthy. So some misrepresentations are valid, maybe. It's one thing to write a book like 100 Years of Solitude and quite another to write a book you represent as investigative journalism and then make very subtle false changes.