It’s a difficult one. In real life, Kyle was a complicated character to say the least, and a proven liar unfortunately (ask Jesse Ventura). The impression I got in the film was that as it progressed, Kyle became one of a diminishing band of true believers in the cause. The scene with his brother is devastating, but he never breaks from his own Manichean world view. I really disliked the film on first viewing, mainly because of all the clichés in the script (when the guy starts talking about wedding rings, you know he’s going to die). But there is a lot more going on, and on secondary viewings, you can more discern that the story that Eastwood is telling, and Kyle’s own story, are not necessarily the same thing. As a last point, I thought the film handled his murder very poignantly.