Every oneworld member can display any e-ticket issued by any oneworld member, even if they're not on the itinerary. S7 can pull up your domestic AA etkt if for some reason they/you really wanted them to. Awards, IT/BT, whatever - all etkts are visible to all airlines (unless something corrupts the etkt record, like an Amadeus etkt containing with a colon [:] in the fare basis field - Sabre can't process that, but then the : shouldn't be used anyway).
Once the etkt is displayed, the oneworld member of your choice can then exchange it, again, even if they're not even 'supposed' to. No limitations on invol reissues but policy restrictions for voluntary changes on certain ticket types, and by fare rules for other types.
Each airline sets its own policy on what they won't do with another member's etkt - most won't apply mileage upgrades, certificates, etc. Some restrictions are as good as a can't do it, even if it's technically possible to do it wrongly.
Source - experience, internal oneworld ticketing agreement