I find it difficult to comprehend the argument that the pilot didn't have the skills, or presence of mind to enter and sustain autorotation.
The report makes mention that the variation of Nr above and below 97% corresponding to a reduction in speed shows an attemp to enter autorotation. Flare might well have made the initial recovery of Nr possible but then after flare effect diminished, it became unsustainable.
I can't find any mention in the report of a check of collective control rigging.
Also, what about snagging the collective? I've not flown the 135 or indeed know what is carried in the cockpit but could a foreign object have found its way under the lever and stopped it being lowered fully? It wouldn't be the first such accident in helicopters.