Have I missed something? The reports seem to skate round what I was told actually happened.
On the B727, when at altitude, like FL390, is was not uncommon to pull the CB for the leading edge devices and then select Flap 1 with the lever, (which operated both slats and flaps), as Flap 1 did not change the camber of the wing, the flap went straight out and only increased the surface area thus giving a bit more lift and improving the Vs1.2 margin. Very non standard but OK if it worked. In the case of the TWA incident the wrong CB was pulled, the trailing edge flaps were inhibited and the slats started to deploy when the lever was moved to Flaps 1 causing the aircraft to go temporarily out of control.
If that has already been clearly stated somewhere and I have missed it, I apologise and will delete.