An update for those who are interested:

After the saga of AA telling me that they will cancel the whole booking - I just got a phone call from the same person who rang me the other day and said that she made an error!!

This is what AA had to say:

It is possible for AA to ticket a RTW ticket even if AA is not the governing airline PROVIDING that the passenger has specifically requested AA to issue the booking. That is to say a booking made by the passenger himself and NOT through a TA. BUT AA prefers passengers without AA segments to contact the governing OW Airline.



If you read between the lines - it means that AA does not want to be liable for the additional cost for re-booking should there be any schedule changes. This would obviously incur work for them from which they are not getting any revenue. I assume that they are forced to issue the booking as they are obliged to under Oneworld rules.

On another note - AA agent gave me an ex-LHR price which is insanely high so I'm waiting for them to get back to me with an ex-JNB quote!