I teach brown out (and green out-under NVG´s) landings and take-offs...i do it with low time pilots, but also with experienced pilots...
You would be shocked to see how many of them don´t cover the "dust landing" point in their "landing briefing"-and how many think they know how to land in dust conditions-and then are totally shocked, when the dark cloud is catching them...
Again: The report will show how experienced the crew was....and might show, what has really happened..
Up to this point, a mechanical failure is still possible (although unlikely).....
I just feel sorry for the pilot-he has to live with the the thought of having killed one of his colleagues.....