Great post on identifying individual failures. It's a damn hard thing to admit to an inadequacy or error that lead to severe injury to one's self, or others.
It seems just as hard to pick up the pieces and make the effort to improve.

My one contribution to this thread, and I am mostly making this statement because of those that have made comments or may be forming ideas that are not really correct with regard to training.

The military as a whole, and the USMC specifically, have learned from these kinds of mistakes that the marksmanship standards from years past were not sufficient on a modern battlefield. There have been significant improvements and changes to their programs that does teach how to fight with the weapons provided. Everything from speed reloads to multiple targets on the move to unknown distance night shoots are taught, evaluated, and ingrained, based on a standard. It is a shame that it took death and grevious bodily injury to get the system to listen to what has been said for many years, but at least it has finally happened.

If individual units are not performing up to the level of marksmanship training expected by the individuals I recomment that they look up the shoots and lesson plans and see what's up. Individual unit failure is just that, and they should, nay, must be held to task. After all, it's your life.