A friend of mine suggested this is might be a partial repeat of the XL888T crash at Perpignan. Not the flight testing part obviously, but that part where water gets into the angle of attack sensors, freezes them in place, so computers think the plane is descending and command an ever increasing pitch up untill it stalled out and plummeted toward the water.
Not being technically minded, I thought I'd throw it out there to you wolves to tear apart.