Surely in any aeroplane, if it starts an abrupt uncommanded change of attitude you'd instinctively place your hands on or very near to the flying controls. If the aircraft initiates an aggressive pitch-down you'd have a quick glance at your IAS and, provided you're well away from the stall, you'd apply a suitable nose-up pitch command. If that didn't work (and assuming the stick actually moved) then perhaps you might now start to fault diagnose. If the stick didn't move, then that would hopefully initiate an alternative plan!