There is something very wrong with the system if this is the best the airline involved could come up with.
I'm sure there will be a few American passengers on the phone to their lawyers...and probably rightly so on this occasion.
Oh please, what exactly was the pain and suffering here? The passengers could stay on the plane in their seat if they wanted to, or they had the option for a walk in some gorgeous sunny Australian weather. It was sunny and about 15 degrees - perhaps a bit chilly if you didn't have a jumper, but still a bit warmer than the point of departure.
They were provided food and although the line-up behind the food truck is a bit comical, it's hardly pain and suffering. I'm sure people who physically needed to be brought food in the plane would have been provided it.
The airline apparently had spare pilots in Sydney and got them to Canberra as quickly as might be imagined in such a scenario. If they didn't have this option they would have needed to charter Qantas or Virgin planes to fly them back to Sydney anyway, right, given that Canberra isn't a port of entry? How much extra delay would that have added? It would have separated them from their baggage too.
What exactly would you propose they do differently?