Dallas Dude
I never met Basil but I used to drink in a pub in Wraysbury, Middx in the early seventies with one of the design engineers on the DH Trident. He was vehement that the wing did not require leading edge life devices and was appalled after the Papa India accident.
Yes, if the droop had not been selected up at such a low speed the accident would never have happened. But the many inputs both learned and facile over the years into why that selection was made have only clouded the issue.
A simple speed interlock switch was the fix, so that you could not physically move the lever to retract the leading edge droop below a safe speed. The concept of building into civilian aircrat a facility to prevent a pilot from selecting an unsafe mode was not even a design consideration in those days.
As to the training aspect, it was a classic case of the simulator tail wagging the line dog. We were programmed like Pavlov's dogs to pull the overide lever of the stick push whenever it went off in the simulator. I surmise that the crew reacted to their training and pulled the overide lever when the push went off. We flew many similar departures in the sim after the incident without over-riding the stick push, and most of them were flyable from the incident height of 1200'.
But please remember that this was in the early seventies when concepts like Negative Training were still at an academic stage and were not part of airline training. We have all learned much since then.