I guess MD900 Explorer's comment about the wind causing the accident [and who knows it was not the wind?] may have been reasonable comment on the early news reports appearing on the net that sought to make a link between alleged windy conditions and the outcome. That speculation appears to be missing in later reports.
On the face of it the circumstances do appear very different from the recent [December] German BK117 accident where again the top half parted company with the bottom half. But if the outcome of that 117 accident might eventually be put down to the 'drive train' coming to a sudden halt during the known/proven impact with parts of a building it may be worth speculating that perhaps something 'stopped' up top again this time on the 109 .... engine/gearbox? That would of course be far more worrying than the speculated 'best option' of ground resonance.