As OneWorld Emerald (AA EXP), if I fly (for example) LHR-LAX-HNL on AA in Y, then I have access to the Admirals Club in all three airports as I am on an international itinerary.

A friend tried a similar itinerary, but connecting to AS recently (LHR-SEA-PDX), and apparently the rules are different. Looking on the AS website, it appears that Alaska Lounge access is only permitted for Emeralds departing on an international flight, and not on an international itinerary as above.

Am I understanding the rules correctly? Thank you