og,

LRD is talking about an Award Ticket, not a OWE. And I would say it's very risky in this case because the ticket and the reservation are linked (and can't, as far as I know, be unlinked). So if you no show one sector you will probably have the whole itinerary cancelled. If you really have to do it then I would ring AA about 30 mins before the departure of the flight you aren't going to take, tell them you have some domestic crisis, will miss the flight, and will make you own way separately to the next city. Then ask them to make sure that the subsequent sectors are not cancelled. It will probably work, but you do run the risk of someone checking and invalidating the whole ticket and/or taking a load more miles off you for what the ticket as used should have cost.

By the way, on a OWE ticket throwing away one segment is no problem at all provided that you get the ticket issued open dated and separate from the reservations.