Re: Black box?
There's a much easier way - just look at the maintenance logs. Any pilot worth their salt who is flying a plane where one of the engines just throttles up all by itself enough to supposedly yaw the plane is going to log it and ask maintenance to inspect the thing. If they're paranoid enough they might even shut it down completely.
Also, IIRC, the "black box" records the position of the various controls directly so if this hack really did occur then it would not be logged in the flight data recorder.