OK, let's look at it from a legal, judicial standpoint.
The airplane was not yet delivered to its new owner. Therefore this could be regarded as an internal Airbus manufacturing "incident". It certainly was not a comercial flight with paying passengers on board. Therefore certain legal guarantees are not provided.
I only fly airplanes, and I have no knowledge whatsoever about legal stuff. But I can imagine that Airbus is not obliged to provide any information as to the chain of events that led to this incident.
So maybe we will never find out what happened? Perhaps someone who knows more about legalities can comment on this....