Well, since we are all jumping on the speculation bandwagon I might as well join in.
One of the three most useless things in aviation is "runway behind you" and I suspect that many pilots who can plainly see the start of a runway might well be inclined to simply aim for it as a touchdown point, rather than the actual displaced threshold, and do so without necessarily considering the reason for the displacement. A low approach resulting in contact with the trees may have been all that was necessary for this tragedy.
Such a tragedy all the same..