Again, if it's true then I'm surprised the F/O didn't pick it up themselves. Perhaps they have done the special sim work for ZQN but currency expired the day before or something, and no one, including themselves, realised until it was way too late?
Not saying it excuses it as the systems should be in place to pick all of this up, but I'm sure someone on this forum has driven with a technically expired driving license they forgot to renew, for example.
I'm thinking really outside the box here. What if it's something weird like the systems exist, but the competencies in training & crewing system at VA is designed to expire at 23:59:59 UTC. The flight leaves at 23:45 UTC. No flags come up as a result, but as the flight is technically operating the next day (as AEDT is +11) the pilot is now not current and cannot operate to ZQN.