Old engineer;
Thank you for your extensive and elucidating analysis. There are however a few details that I don't fully understand. For example:
The only way that reasonably low forces (low to my mind, anyway) can remove the VS at water level is if there was prior damage to the aftmost anchorage area of the VS, making both clevises ineffective. Damage in this area is up in the carbon-composite.
Could you perhaps elaborate on this? The mid and rear attachments were all recovered with the V/S and no damage to the carbon-composite parts was reported (*). The only damage to composite parts was in the back-up structure of the front attachments which separated from the V/S and presumably remained attached to the fuselage.
regards,
HN39
EDIT:: (*) Except the damage caused by the rearward rotation of the frame assemblies.