Looked pretty cool from where I was sitting to see a 330 takeoff and turn left from 16R. Caused a few collective gasps I can tell you.
Great job from ATC, especially departures. Kudos to that man. There was a brief pause while he and TWR worked out WTF was going on and then departures resumed as normal with a single controller managing Air Asia stooging around with no primary flight instruments and all the normal departure flow.
I'm guessing they headed to Melbourne due to the weather. It was reported as few at 3000, which was a lot better than the basically overcast at 2000 at SYD.
I'd still like to know why they turned left though. Even though the FMGC may have been saying turn left, self preservation should have kicked in and said, 'Turn right or at least go straight ahead -
away from the other runway.'