Groaner,
Y'know, the thing that gets me is the Qantas auto-response "There was no risk" and "There was no flight safety issue".
That's the same as saying "There are no holes in my Swiss cheese." When there clearly were in this case.
May I suggest, that if you want to talk in terms of the Reason model, the Qantas spin doctor response was really saying that the holes in the swiss cheese didn't line up.
For whatever reason a go-around was performed followed by a safe landing. One of the defences in place prevented an attempted landing in an unsafe configuration.