Actually, this is not a FifthFreedom flight since it involves two cities witin the USA and QF has no local carriage rights. Having local carriage rights would be Fourth Freedom rights, or Cabotage, permitting a foreign airline to sell seats on domestic legs of that foreign carrier's flight.

Fifth Freeom rights involve a second and third country. That is a flight arriving from the "home" country of the carrier into the first country's airport, then continuing on [as a "stub"] to a third country. The carrier is permitted to sell seats on these transborder segments since all deplaning passengers must clear customs and immigration at the final destination. [I believe QF does this between MAN and AMS or FRA. CX does this on its JFK-YVR-HKG flights, selling to anyone who wishes, seats between New York and Vancouver. ElAl has just started doing this on its continuing flight between TLV-YYZ-LAX, for those wishing to just travel between Los Angeles and Toronto.]

Not having Fourth Freedom rights means the flight is not for sale by QF to people wishing just to fly between JFK-LAX or LAX-JFK. However someone originating in SYD on a QF ticket might be able to fly into LAX and stop-over, then continue on the QF flight a few days later to JFK, but only if the inbound QF flight from SYD clears US customs/INS/Ag at LAX, which is unlikely. Somewhat more likely is the ability to take the flight between JFK and LAX, if one originally travelled from SYD to JFK. Since no customs or immigration is required to depart the flight at LAX, it would not be considered sterile until it departed LAX [though QF may consider it sterile and passengers boarding at JFK likely can buy airport duty free so local carriage even of these passengers is unlikely].

Did that make any sense?