Some strange ideas cropping up on this thread. Maybe some clarity would help:
1. Autorotation (AUTO) - The rotors are driven only by the airflow up through the disc.
2. EOL - the thing you do at the bottom of an autorotation. (If the engine is running with zero TQ (typically at idle) it is a"Simulated" EOL.
3. During autorotation, if the engine is producing ZERO Tq, the only friction difference between that and the engine shutdown, is the increased rotational Delta speed of the inner and outer race of the freewheel. Compared to the Autorotational forces acting on the rotor I suggest this difference is inconsiderable. Assuming of course the freewheel is serviceable and the TQ during autos with engine at idle is zero.
4. Having spouted this, I have no idea how a H300 works. Saw one once from about 300 yards.
Sad for this guy but I would say if he planned a deliberate entry into auto, something we all practise a lot in our initial and other training, it's difficult to assume the pilot screwed this bit up. Maybe something else, like seized freewheel, intervened.