I agree that the treatment of Vietnamese history was a little thin, unfortunately, and that he neglected the Vietnamese who fought at Dien Bien Phu. I also noticed some factual errors. As with his other series, people aren't going to like some of the things he does; there were some major discussion what he emphasized and left out in his Jazz series, for example.
However, on balance, I think it's been good so far. He could have added more details about the plotting by the Generals to overthrow Diem, the various crosses and double crosses but essentially I think he's gotten it right so far.
At least he has people watching, which can lead to people finding out more than is shown.
Getting back to tonight's episode, I thought it was interesting that one person said his earliest recollection of Vietnam was the Buddhist monks burning themselves. That was mine too. I remember reading about it in Time magazine; I was about 12 at the time. I also remember Madame Nhu. Oddly enough, I don't remember Diem's overthrow and murder but do remember about the monks and Madame Nhu.