Absolutely agree with the open dated tickets.
Also have your travel againt book you again on the flights in question. He can use a separate reservation record, so AA does not see the onward reservations.
It seems to be a problem specifically with AA - they are very strict in changing dates when you call them. I found it much easier to have my travel agent change the dates. Even the PlatEx people dont want to touch dates on RTW tickets and you can spend hours on the phone with AA for just a simple date change (and space available on the new date).