The event was clearly the result of Mishandling of the primary controls during a normal encounter with changing wind conditions during climb.
The aircraft raw data in the Report shows the following.
The FO extended the speedbrakes and LEFT THEM EXTENDED extended for nearly 60 seconds until they were auto-retracted by the activation of Alpha Floor. The speedbrake lever eventually was selected to the retract position by the Captain on his return.
The FO selected the Thrust Levers to near idle (on the second occasion) just as the aircraft was entering (high) Alpha Protection. He did NOT select the Thrust Levers to TOGA in accordance with the FCOM procedure when Alpha Floor was activated. The Capt selected the throttles to Climb on his return.
The ATSB Report on the incident is woefully inadequate in addressing the primary and secondary causative issues and indicates a lack of understanding and thorough analysis.
There are very clear inadequate training issues to be addressed and they were not identified by the Report.
Good airmanship dictates that when using the speedbrakes it is advisable to always leave one's hand on the lever until they are retracted (except momentarily for other control selections) so as not to forget they are extended.
At high altitudes especially, speedbrakes should be the primary method used to prevent overspeed when excessive speed trends occur. Thrust reduction is not effective in the short term to stop an excessive speed trend close to Vmo and the engines take forever to spool up again from idle.
In case of actual overspeed, FCOM procedures should of course be followed... which normally includes Thrust Levers to Idle and Speedbrakes extend.
The FO exhibited classic symptoms of sensory overload...something that proper simulator training in high altidude speed excursions would easily address...
Alas I fear the message has being lost in the smoke and mirrors of the Auto Flight Modes understanding or non-understanding, usage or non-usage arguments.