This aircraft hit the trees, and the right wing, engine and propellor seperated from the fuse early in the accident sequence. How anyone with any credibility can look at photographs and say there is any evidence that the r/h engine was not producing power - is beyond me. Fair enough if it had been flown level into the side of a treeless hill - but not the case here.
So I would discount any "evidence" that the damage to the propellor blades and hub are proof that the engine failed.
In fact even the expert does not say the engine was not delivering power. He says the propellor was not rotating under power at the time of impact. I think this is probably right - because at the moment of impact (to the propellor) it had already been seperated from the engine and/or the engine from the wing and/or the wing from the fuse.
IMHO
Di