I was flying a VC10 on a flapless approach once when the stick pusher activated way above the correct speed. Fortunately I was able to overpower it and had the system dumped.
We found several faults:
1. An AoA probe was sticking. Instead of moving smoothly, the sudden movement was detected as a rapid approach to the stall, triggering the stall protection system earlier than normal due to 'phase advanc'.
2. The aircraft was just back from a prolonged detachment to a dry, dusty location and hadn't been washed for ages.
3. On another VC10, the 'lift rate modifier' which changes the stall protection AoA value with flap/slat configuration hadn't been connected for some years. The cables were neatly tucked behind the aircraft panelling.
4. On that same aircraft, the stall dump lever was inoperative - because a vital pin from the linkage was missing. And had been for many years, as the surface condition of the hole through which the pin should have been fitted bore witness.
This placed rather a lot of doubt on the quality of rebuild carried out prior to delivery to the RAF. As did the fact that the engineers found an ex-BOAC silver teaspoon in the bowels of the aircraft! It had flown with BOAC, then been sold to Gulf Air, then rebuilt as a VC10K2 and flown for years by the RAF until it was discovered.....
All in all, the stick pusher was a complete waste of time. More trouble than it was worth; with 4 people keeping an eye on the IAS and a reasonable stall warning system, the wretched stick pusher and klaxon system was completely unnecessary.