The rule is listed in several versions, this one is off the
oneworld site:
4. FLIGHT APPLICATION/ROUTINGS
Fares only apply on any AA/AY/BA/CX/EG/IB/JC/JL/JO/LA/LP/MA/NU/QF/RJ/XL/4M flight.
- Travel must be via the Atlantic and Pacific Oceans and only one crossing of each ocean is permitted.
- Travel must be in a continuous forward direction between TC1 - TC2 - TC3. Backtracking within a continent is permitted except as follows:
Backtracking between Hawaii and the Continental USA/Canada is not permitted.
- Only one intercontinental departure and one intercontinental arrival permitted in each continent except as follows:
- Two permitted in North America. when one is a transfer without stopover.
- Two permitted in Asia when one is a transfer without stopover or on direct single plane service between the Southwest Pacific and Europe.
You have already used the "
... one is a transfer without stopover or on direct single plane service" part of the rules, so if you have not yet otherwise visited Asia you should be fine.
Note that you require an additional segment to return to Oz via Asia- if you already had maxed at the 20 limit originally you may have a problem.