A terrible ride down for sure and nightmares all round for family members, be strong guys.
From the following bit of the NTSB report, and I have not had the luxury of seeing a hydraulic R44 with its clothes off, but how long is the connecting push pull tubes to the servos? I see also that they don't appear to really tie up whether the jewellery is missing from top or bottom of the tubes.
Examination of the flight control system revealed that the right forward servo to swashplate push/pull tube fitting was disconnected and the attach hardware (bolt, lock nut, two washers, pal nut) was missing. The left forward servo to swashplate push/pull fitting was connected; however, the lock nut was found partially engaged on the bolt threads and the torque was "finger tight"; no pal nut was noted. The aft servo and push/pull tube fitting was secured with the appropriate hardware.
Of course there is the possibility that the missing bolt broke because of stress loads at impact.
<I have seen that on other types often enough>
There will be all sorts of stress marks on the yoke etc, regardless.
However I really do hope that an extensive search with metal detectors is undertaken to lacate all bits missing.
If it was the upper bolt then it could have popped quite aways for sure, maybe there's a few old beach-bum-geiger-counter-toting-hermits in the vicinty that would be only too pleased to wander around with their machines. some of those guys are unbeleivable the way they uncover all sorts of ironmongery.
A micro examination of the other "loose" nut should easily determine whether it is loose as a result of stress load or a mistake.
Those 'pal nuts' are not things that anyone would hang their hat on with any sort of a bump???
I would think that it is very hard for a "mistake' on two components especially if the one remaining was still secured correctly and it was all done by the same gentleman.
The sound effects are abit puzzling and regardless of experience of the observer it is amazing how people rmeber what came first after a traumatic event. But the pop twang, different noise level and flick roll could be indicative of something much more sinister out on the end of a blade???? There do not seem to be any reports on the health of the rotor blades.