The droop lever was mechanically locked in the 'extend' position while the flap lever was in a 'flaps-selected' position. When the flaps were selected 'up', the droop-baulk was removed.
That was the only lock in place (no speed-lock), so the flaps on PI had been selected fully up before the droop was moved.
After the accident, the company painted the droop handle with red & white stripes (if memory serves), and we all became utterly paranoid about monitoring LE/TE selections!