My inlaws traveled from USA to Singapore and just boarded their cruise. The day before they got on the ship, Air China changed the time of their return flight and made it impossible for them to keep their schedule.

Their UA award ticket was booked as an open jaw. Specifically, they were IAD-BRU-SIN (layover in BRU, not stop). They paid to go from SIN to REP and then paid another ticket to go from REP-SIN.

The return of their award ticket was from HKG-PEK-IAD (layover in PEK, not a stop).

I was able to find 2 seats in biz on CX returning from HKG-ORD-BWI for 55k AA points each.

Their original flights were at the saver level (1st all the way).

No seats were available online Saturday at the saver level for flights that were possible for them to make. I didn't want to use more points or have them fly in coach.

When I first (on Saturday) asked UA about cancelling the return flight (so I could fly them home on CX) they said I couldn't get the points back for the unused portion because the ticket had already begun. I was able to get a supervisor on Monday who opened up the seats at the saver level.

So my question (finally got there!) is this: Why book a RT if you could book 2 OW's? I'm asking for simple itineraries, not crazy ones...I believe you can book OW's on UA and AA but not many others. Obviously I'm only talking about the airlines that allow the OW's. If they had booked 2 OW's I could have cancelled and booked on CX (probably way better in biz than UA first).

This would also be good if you were looking for a better return flight and one popped up when you were on your trip.

I hope my question is clear. Thanks for all your thoughtful responses. Please feel free to ask for clarification.