I don't know how accurate the information is but the Qantas Source reports that VH-OQF had a minor tech issue prior to departure from DFW on 28/2 and that the decision was made to divert to BNE due to a crew hours issue,apparently the crew would have enough hours to make it to BNE but not SYD.
The pax on the flight were transferred to domestic flights to complete their journeys.
QANTAS A380 VH-OQF QF8 Brisbane Diversion. | The QANTAS Source
Cheers
Paul