bearfoil;
I suggest it is not indicated that the tail hit first ...
I think you are following my thread of thought, i.e. the vertical component of the impact was so high, that whichever part of the aircraft touched the water first had little bearing on the outcome, as various parts of the structure disintegrated almost instantaneously as the horizontal and vertical moments were cancelled out by an impeding wall of water and buoyancy moments respectively.
I envisage that the "hand-clap" effect to the wings was extreme and coupled with horizontal impediment they sheared off at the now crushed wing box root.