root cause
To be honest, if no major upset is demonstrated getting the root cause of this accident will be mission impossible - Maybe even if the CVR/FDR are found.
You would probably need the readings for each ADR and IR channel to each of the PRIMs at least to identify an electronic fault if any - something that probably isn't availabe in the A330 FDR.
I suppose that it is time to give more attention to computer systems - and specialists - when dealing with aircraft accidents - be it Airbus, Boeing or whatever a/c involved.