A week later all live fire was banned, due to fire danger. I always thought the "split bullet" theory was a little odd. I was learning, even then, that maybe "The Word" was rumor and gossip writ large.
You were there when I was there. We had just finished the course when they pulled us all aside and searched for any saved rounds and then told us what had happened. I had to wait for orders in casual and I got to read the report in the battalion office. The theory was reasonably convincing and the pictures of the round fragment that hit him indicated that something had fractured it before it hit him. There were fixed 50 cals firing at the time, we were at the top of the hill watching while that group was going through and they were definitely firing. The dispute in the report was whether or not it was the tip of a 50 cal round or an M16 round; there was no way of telling.