Looking at an "enhanced" version of the full video posted above, the tailboom folded in the same plane as though the LH mount(s) failed. And with the 5 degree offset of the vert fin it seemed to follow that direction. Then everything else let go. Will be interesting to see the whats still attached to the tailboom. While there have been cases where a tailboom was lost it wasn't at speed like this one was. And since they have pics of where the components landed, I would think they would find them sooner than later. To me if he had felt anything in the drivetrain before that he would have been slowing down and looking for a spot to land which he had plenty in that area. Unfortunately it looks more like it was an instantaneous catastrophic event.