The vertical stabilizer had come off, essentially leaving it as an uncontrollable craft. That's my guess.
MM
There was a Japanese 747, maybe 20 years ago or thereabouts, that somehow lost the vertical stabilizer. (Collision with another plane? I don't remember.)
Anyway, the pilots managed to keep it aloft for quite some time by gingerly handling the engines and the remaining control surfaces, but they were not able to land it.
When I looked at those pictures of the snapped-off graphite lugs, I was surprised that they'd design the tail that way. They have the thing attached at a very high-stress point, it's IMO asking for trouble. If I was desiging it (I'm not a designer but I do have some common sense), I would have the graphite panels extend through the plane's body, and then attach them to the inside/bottom of the tail end of the body. That would put the least amount of stress on the attachment points. It would transfer torque to the body (at the top of the body, where the graphite panels would extend through reinforced slots) without stressing the attachment points, and also allow a bit of "flex", with the slots at the top of the body acting as a sort of fulcrum.
IMO this design would handle excessive stress a lot more gracefully than the actual design which places the attachment at the highest stress pont.
Look at how 2x4 studs are put together -- they dovetail two pieces of wood end-to-end so that there's a lot of overlap. If the guys who designed this plane were designing 2x4 timbers, they'd just take two sticks, put some glue on 'em, and stick them together end to end.
It doesn't take a degree in rocket science to predict how quickly a 2x4 like that would fail if subjected to any lateral stress. It looks like that logic escaped the guys who designed that plane.
If I ever fly again, I will never get on one of those Airbus models. After the nightmares I've had before 9/11 (when the pilot says he thinks he'll be able to land it, after circling for an hour with a jammed slat), I tend to be a bit wary.