IIRC the fatal crash of XV180, shortly after takeoff at RAF Fairford, on 24 March 1969, was attributed to one the props going into Reverse. The aircraft then stalled.
Yes, it was:
During climb out from Fairford, Gloucestershire the captain asked the co-pilot to feather No4 engine. However the engine went into full reverse thrust which rendered the aircraft uncontrollable. It entered a starboard wing over, crashed and caught fire. All six on board were killed
UK Military Aircraft Losses