If it was a domestic configured A330-300, then 10 flight attendants are the CASA specified minimum.
Taking passengers off would have allowed it to operate with nine F/A's.
Notwithstanding any other complaints, I suspect "A Frequent Flyer" is ignorant of these requirements and the F/A's in this case are being unfairly criticised.
I also bet Crikey.com.au would not publish this.