Rickair,
Without going classified, they were within "their" ROE; read between the lines of the story or look for other stories, it's spelled out. Do more research and see the unethical behavior of the MGen and see the specifics of how they preferred charges and how many investigations cleared them. This is another example of leadership setting guys up for failure (ROE they create but won't back) and then following through to hammer them. Also, research how the MGen acted reference that Marine unit.
Also, look at the MGen's statement after charges were dropped, he said that he did it to clear their names! You DO NOT prefer criminal charges in order to clear names, that is NOT how the system works.