That is very weird... Did you try calling again?
As far as QF is concerned, Hawaii is included in their definition of North America according to
this chart on AS.com
So that rules out my original theory of Hawaii being its own unique region, which is not the case here.
As a matter of fact, SEA-HNL-SYD is shorter than SEA-LAX-SYD.
I would try calling again and hopefully this time around you will get it. Time is of the essence when it comes to QF F awards.