With an engine shut down on a twin, if you land at the nearest suitable airport you have covered your backside. I can’t recall a single instance where a regulatory authority have taken the position that a crew should have pressed on to the destination on one engine.
According to the ATSB you can fly for as long as you like on one engine if you are a foreign carrier. However VH aircraft have to land at the nearest suitable airport.
Interesting that they are suddenly all so concerned about glide range yet if you read the multiple Air Asia reports where they flew for hundreds of miles past numerous suitable airports it doesn't even rate a mention. Why does the glide range matter in this incident yet not in the other ones?? Since when has glide range in a multi engine jet even been a legal consideration anyway??
I agree they should have landed at Geraldton but the ATSB need to find some consistency in their reports and start applying the same standard to all carriers.