I have no reason to doubt that all players in this tragedy knew CAS briefs intimately.
I would be very interested to hear who the 'key personnel' mentioned were as it seems possible to me that one was the (nationality unknown) JTAC at or near (very important distinction) the scene. Of course I may be wrong and as I wasn't there that remains simply a personal suspicion.
Let us also consider the fact that the PB hadn't made it onto mapping despite being 'ours' quote <<for weeks>>. My point being that there is a chain of events here, not just one trigger squeeze. If the drone, the AH and whoever they were talking to (air support having been 'called in') were all of the opinion that this was a EF position (or didn't pipe up despite thinking the opposite) then this has to be a more in depth failing than a single operator messing up.
In a partial answer to BEagle's query. One of the important concepts about a lack of SA is that you may well think you have complete SA. One might be unaware one was confused or even in a confused situation.
Key point. Hands up who thinks that passing friendly position as implied in the article (not...repeat not...as per line 8 - there is a massive difference) is a great idea? I'm pretty sure the last time something like this was being hauled through the press we were debating why on earth the CAS crew had been given the friendly posit.
Lastly. It might well turn out that someone was negligent or incompetent or even criminal. It might turn out that all players were simply trying their hardest in a desperate situation. A tragedy nonetheless.