Ornis - I was just offering opinion on the reasons why a mass grounding was unlikely, given the number of machines flying safely & the lack of other related incidents. I tend to deal in what I know and can deduce from photos, as eye-witness reports may be valuable to the AAIB, but they're generally a little instant on a thread like this, so best treated with a pinch of salt.
As others have intimated, I feel it unlikely that this aircraft came down vertically, from significant height, with rotors stopped. It is possible that the rotors were almost stationary in the very final stages, after most of the energy had been dissipated in any flare or cushioning, since there is neither any apparent rotational damage to main or tail rotor blades. In addition, it would be a surprise if a near vertical, rotors-stopped, impact from anything over about 50' would result in as little damage to the airframe. "Little" is sadly relative, of course.
Others have mentioned coning angle - the 135 has such stiff blades that there is almost no coning angle.
Another small point to note is this was probably a 2.5 tonne weight when it came to rest = 2910 MAUW less 400kg fuel for 2 hrs flight.