Two scenarios require decreasing the pitch: failure of one engine and stall. If you are at Vyse and lose an engine you will go below Vyse if you don't decrease pitch. Fundamental law of aerodynamics. This sounds like either a Vmc roll over or an uncoordinated stall. Both of which are pilot error sadly. The King Air is a wonderful airplane, but just like aviation in general is terribly unforgiving of carelessness, error, and neglect. Hope the NTSB can make a proper determination as to the cause of this tragic event.
Back in the early 70s I was following an Eastern DC-9 on the ILS into FLL in very heavy rain and turbulence I elected to miss the approach early, diverted to MIA and learned that the DC-9 had crashed
