TU.114
So I think it most unlikely that the colleagues decided to run the engine feathered in such a condition instead of properly securing it.
What would shutting off the fuel to the engine actually do to any of the symptoms available to the pilot?
Does not the prop continue to spin slowly even with the engine shut down?
No withstanding the tenths of seconds of imbalance as the spinner tears away doesn't the final imbalance seem very small considering it's small relative diameter compared to the prop?
Not being there and not seeing the actual symptoms displayed I'm wont to predict what the pilots actually did.