He "killed" him.

I love the way O'Brien tells some of his stories. He spends an entire chapter talking about the man he killed. "One eye was shut. The other was star-shaped hole," he tells us on page 124. He tells us about the mental torment that killing that man put him through. He even tells us about that man's life plans that he cut short by killing him. Then, all of the sudden, he tells us that he didn't kill that man. He just found this guy on the side of the road and that someone had killed him. Though this kind of bugged me for a while, I am beginning to appreciate his reasons for doing this. I actually see two reasons for doing that. One is to describe the mental anguish that the war caused soldiers. Even if a person didn't kill that guy, they were on the side that caused his death. If it wasn't for them, that person may not have died. Even though his death was not their fault, they would see it that way. The second reason is that O'Brien, though he writes from the first person point of view, may not be writing all of the novel form his experiences. I think that the "I" in the novel maybe the all soldiers that fought in the Vietnam War. Though O'Brien did not kill that man, someone did. That same someone probably thought the same things that O'Brien said he did. O'Brien is telling this story not only for himself, but also for all of the soldiers that don't have the chance to write it.