Terry Otway a retired Ansett pilot dying in a Bristell, being a good example.
Actually, it was a Brumby, not a Bristell
A few weeks earlier, at Penfield ALA, the same aircraft had experienced jamming of aileron hard over during flight control "full and free movement" part of pre-takeoff check . That defect was rectified. There was suspicion that the elevator may have jammed fully back during practice stall. Witness saw it spinning before crash but no evidence it was being spun deliberately.
Nothing conclusive but photo of wreckage also showed elevator full up. Could have been caused by impact but will probably never know. .