As you state later, the ROE approved at that level is extremely broad to the point of being more an expression of the CIC's intent than rules on the execution of that intent. The NCA does not dictate tactical level rules of engagement. They don't have the visiblity required to micro-manage at that level in all the theaters we currently operate in.
They do not dictate how such engagements may occur, but they clearly dictate the conditions necessary for such an engagement to occur.
The act of firing on a live target is something that is taken very seriously, and the necessary conditions for this are not left for a field commander (self defense is always permitted). They are clearly defined from above. The problem occurs when the nature of conflict changes. It is difficult to anticipate the impacts of those changes apriori. So if the law of war says we dont fire on funeral precessions, we do not fire on cemetaries, unless we find later that the enemy is using cemetaries in unlawful manner, and then the ROE is modified.
I have no idea if this was the case here. Just wanted to point out that ROE, while not intended to micro-manage the fight, is intended to make sure lower levels do not inadvertantly create a national embaressment, or worse a crisis by mistake.
And occasionally, it has resulted in missed oppportunities.