In the top photo in post #141 four blades look relatively intact. One blade (the one pointing "down" is only partially there (you can see more spar than afterbody and ever then the blade is short). A blade failure could easily rip the rotor, swashplate etc. out of the aircraft relatively intact. It is possible, if not probable, that this could have occurred in a fuselage strike, but that amount of blade loss would easily rip the "rotor et al" out of the aircraft. That kind of failure is generally proceeded with a "bang." As to HUMS there are multiple cases (Bristow 76 as an example) where there was almost no warning of a catastrophic blade failure.
The Sultan