Would it be fair to say that the aircraft was just at top of descent, about to make its final approach into the airfield. This is assuming that the crew had made any control input at all that might have precipitated the sudden break-up.
If so, the rotorhead and gearbox were being unloaded, not loaded. The former might lead to the final critical slipping of the strut retaining pin, rather than loading up the head which might lead to gearbox, strut mounting failure.
As I recall, the bottom of the strut feeds into a fork arrangement where the pin is threaded through two eyelets. Assuming (again huge assumptions) that there were no diaper pins and firewall plate, how far would the pin have to move to release the strut. Would coming out of one eyelet be enough to lose the structural strength of the pin?