I fail to see how that invalidates your looking at LATAM, are you sure that you can't use codeshares (flights sold by AA, and with an AA flight number) as a way to get around, and then credit them directly to LATAM?
Also:
Travel between points outside the U.S. Use of a non-U.S. carrier is permissible if:
* Travel by non-U.S. carrier would eliminate two (2) or more aircraft changes en route; or
* Travel by U.S. carrier would extend the total travel time six (6) hours or more than would travel by non-U.S. carrier.
* Short Distance Travel. For all short distance travel, regardless of origin and destination, use of a non-U.S. carrier is permissible if the elapsed travel time on a scheduled flight from origin to destination airport by non-U.S. carrier is three (3) hours or less and service by U.S. carrier would double the travel time.