" .. If I was to have a guess at what has happened here and it is only a guess, I would say this has everything to do with a certain “OEB” i.e. “UNDETECTED ELEVATOR CONTROL LOSS IN CASE OF DUAL FAILURE” .."
I'm not sure whether the QF Airbuses have the OEB reminder function enabled, or whether the crew referred to the OEB during the event, but in any case the OEB says to "apply normal ECAM procedure and STATUS" if the malfunctions occur in flight, so it would not have altered the outcome.
The vertical speeds which ensued only equate to around 2 - 2.5 deg change in pitch, although the rate of pitch change was obviously large to cause injury.