Is it possible that a contributory factor in this tragedy, could have been "elevator blanketing" at the point of touch down? This can be prevalent on some aircraft at high AA, where the elevator and stabilizer is in "stalled air" from the main planes and is ineffective or control even unpredictable, until the nose is lowered and the elevator is back in clean air.
Just my 2 cents worth.
Apologies if it has been mentioned before but haven't the time to read every page of this thread.