IT WAS REPORTED THAT A PRIVATE PILOT WAS RECEIVING INSTRUMENT FLIGHT INSTRUCTIONS FROM A CFI WHEN THE ACCIDENT OCCURRED. HOWEVER, THE CFI STATED THAT HE WAS INVITED BY THE PVT PLT TO GO WITH HIM ON A SHORT FLIGHT AND THAT HE WAS ONLY A PASSENGER. DURING THE FLIGHT, THE PVT PLT REPORTEDLY STARTED DOING SLOW FLIGHT MANEUVERS AT 3000 FEET MSL. ACCORDING TO THE CFI THE PVT PLT MADE SEVERAL FLIGHT CONTROL INPUTS WHICH TERMINATED WITH THE AIRCRAFT BEING IN AN INVERTED SPIN. WHEN THE PVT PLT MADE NO ATTEMPTS TO RECOVER, THE CFI MADE THE ANNOUNCEMENT THAT HE HAD THE AIRCRAFT. HE STATED THAT THE PVT PLT HAD A COMPLETELY BLANK LOOK ON HIS FACE AND WOULD NOT LET GO OF THE CONTROLS. HE MADE THE ANNOUNCEMENT AGAIN WITH THE SAME RESPONSE. HE THEN FOUGHT THE PVT PLT UNTIL HE GAINED CONTROL. HOWEVER, IT WAS TOO LATE TO AVOID IMPACT WITH TREES, WHICH RESULTED IN THE ACCIDENT.