Originally Posted by skimthetrees

I do not think you can pin this on CX.

I believe this is because AA routing rules do not allow it. As a general rule you are not allowed to transit a 3rd region on one award. There are exceptions but transiting HKG to go from North American to Australia is not one of them. You can find a lot of blog posts on AA award routing rules that go into more detail. You can piece it together with two awards unless the segments are married segment restricted.

IIRC, AS, while not having many explicit routing rules like AA just does allow N.A. to the South Pacific on one award on CX. You used to be able to see things like this on their award chart page but they have revamped it and it does not show it now. Possibly AS will add this if they ever get to OneWorld mixed carrier awards.