Originally Posted by
SwissexLUG
If rules are applied consistently, then it should be 4 continents. The same thing happens when you fly on QF/BA direct services between Australia and Europe (e.g. QF 9 MEL-LHR with stop in SIN). And in this case Asia is counted as a continent IIRC.
This is true, but in the case you mention there is an
explicit rule to cover the Asia transit, whereas there is none for NA transits, so the case could be made that in the absence of a rule against it there is every reason to argue that NRT-GRU does not involve paying for NA. Alas, the airlines are governed more by greed than Viajero logic so I doubt this will fly.