While you Video Geeks are examining the video....consider the actions of the entire rotor system immediately prior to the apparent separation of the one blade from the Rotor Head if you will.
I am wondering how the Rotor System would react to a sudden stoppage of the MGB particularly in the way each Blade would react both individually and as an attached part of the whole Rotor Head.
If the MGB seized and the Mast sheared off.....that would also shear the Pitch Change Links I am thinking.
As that happens very quickly....the effect on the Rotor Blade movements would also be very rapid and should (I am guessing) transmit a somewhat common reaction to all of the Blades.
Meaning to me....the Rotor Head would act more or less in a common manner and not shed individual blades.
If that Rotor Head moved such that a single blade made contact with a strong object (say the fuselage) then I can see a single blade being lost from the Head.
Do you see the whole Rotor Head Tip Path Plane tilting in such a manner or are we seeing a single blade launching off for points unknown while the rest of the blades act in a common manner?