Thanks for the replies sxc, christep and FlyPointyEnd.
Reason given for delay only after we boarded. Weather too hot, not enough fuel to fly all the way back to HK. So need to refuel in Singapore.
No we were not allowed to deplane in Singapore. Sat on the plane from 12:30pm SA time to arriving in HK at 12:20pm. Close to 18hours! I should consider taking the direct flight from Perth to London...
Boarding announced before 12:00pm. Got to the gate and not allowed to board until 12:30pm which was the original departure time. Then when boarded and announcement made, one pax said he wanted to get off. So we had to wait another hour for him to get off and get his luggage. Then there was a problem with the luggage, and had to be counted again before taking off...
Arrived in SIN, refuel and crew change... I think we were there for 2 hours?
Frankly, maybe points/miles better than service voucher which you can only use against buying tix directly from CX...?