Leaving the "bomb" theory to one side at the moment, this will only serve to tarnish QF's reputation at home, even more than it already is.
They've laid off a lot of their Mechs in SYD and farmed out all the heavy checks, that used to be done in house, to the cheapest Asian bidder. If this turns out to be a fatigue/maintenance issue, a lot of people will be saying "I told you so"!!
Good job by the crew. If I got out and saw that, I think I'd be kissing the ground and heading for the nearest bar............