I flew for these guys for several years. Whilst the facts are not known and it could be anything at this stage, I will say that the majority of the Korean Pilots were lost without the G/S. Also, most of them had[have] a tendency to push forward and undershoot the Glide Slope in the last couple hundred feet in order to have a lower angle in the hope of the "smooth landing". These guys were obsessed with the smooth landing. Word got around about me, and when they flew with me they knew never to undershoot when I was next to them.
I am saddened by this news, although not surprised based on my personal experience.