The way this works is that while there is an entry on the pricing system, a travel agent can take the fare basis and apply it to certain types of routes and airlines. This ticket - which is no longer sold by BA either - was set up as ticketed on BA or QR and if you look at the fare rules you will see the routings and airline options for this. If a TA sent a given itinerary into the ticketing algorithm, it should come up with the cheapest option and will typically present in this case both BA and QR flight numbers along with identical cancellation rules.

Though BA no longer sell this fare basis, there is a new fare basis which closely emulates the one used by the OP, whereas looking at main GDS, AJR9R1FO allows changes, either without fee or for USD50 in some scenarios, and allows a full refund for cancellations.