All changes and reissues were made by AA. There are/were no open sectors.

[btw, the cause of the 3-way conversation was due to my not being able to OLCI a next-day BA departure ex-EZE. [My wife, on the identical itinerary, with a separate PNR, had no such problem.] The BA agent said that their system was unable to see my most current ticket number, and needed AA to resend it. The two agents spent over a half-hour on the phone together trying to diagnose what had gone wrong (and was continuing to go wrong) with my ticket, and amidst everything else, they both asserted that I needed to convert to a paper ticket before the CAI - AMM flight, as though this were obvious, common knowledge. If I had heard it from only one of them, I would certainly have ignored it....]