"Didn't I read somewhere that they "removed" the limits to the elevons to make a more impressive flight demonstration? That's what caused the canard failures?"
That or trying to avoid the Mirage(?) that was allegedly flying in & out of the cloud above photographing it.
Saw it the day before when it was first on line ahead of Concorde, the next day they swapped slots. Not biased but the Concorde display was far more energetic than the 144 on the Saturday. Whatever caused it it was a tragic accident.