F/E now acts on his own ...
Had a similar incident on the Electra years ago where the F/E pulled the handle (in the blink of an eye and during the landing flare, mind you) when a prop decoupled.
Post flight, we thought that his action showed initiative .. but that it might have been better had he consulted with the pilots prior to doing something which could have had significant consequences.
I presume that a like discussion occurred after your example ?