I think the point here was that the guy possibly wasn't specifically trained to confirm the engines were shut down by checking NH was zero. Assuming that he knew and understood not to move the condition levers out of fuel off until the engine had shut down, it seems to me that he thought the engine was in fact shut down. The reason he moved the levers out of fuel off was in an attempt to diagnose a possible rigging issue, something even an idiot wouldn't do if they thought the engine was still running.
I think you are treading into engineering territory Deadhead, when you write about checking rigging. That's the domain of the engineer, not the pilot. As a pilot, there is nothing in the Bombardier manuals which require the pilot to carry out engineering tasks. An engineer would carry out the procedure him/herself, rather than asking the pilot to do it. After all, they have a far more intimate knowledge of the donks than us.
Nevertheless, the specific case in question is out of my domain. I don't know whether it was pilots or engineers at the controls, and what the circumstances were behind the events. I just hope no-one gets crucified over what mos likely was an innocent mishap.
There's no requirement with the PW12x to monitor Nh or Np to any specific value as the engine runs down. The reason is that the condition lever remains at fuel off until the next engine start. Unlike the Garrett, where you hold the engine stop buttons in until a certain RPM. (for different reasons)
As for the subject of this thread, I have no idea whether pilots or engineers were at the controls. I just hope nobody gets crucified over what was probably an honest mishap.