I'm struggling to understand some of these arguments.
The length of flight is irrelevant. The cost of the flights is irrelevant. A service was purchased and this was not delivered as purchased. A business class upgrade or enough points in compensation for a business class flight on that sector would be the minimum expectation.
What if the routing was ADL-SIN-LHR in business and there was a downgrade of the ADL-SIN leg to ecomomy? SIN-LHR is more expensive than ADL-SIN-LHR. That in itself means absolutely nothing and shouldn't factor in the calculations. I'd expect full compensation for an ADL-SIN leg or the difference between business class on that sector and the cheapest economy fare not the walk-up economy airfare.
This response is no different to the response we've bern giving on the Qantas downgrade threads.
@Caversham04, don't take any notice of some of these comments and keep fighting for compensation.