Originally Posted by
Schultzois
The question marks for me are whether, if his roundtrip in J is indeed booked as a roundtrip redemption (as opposed to two one-ways, which is what I generally do in order to retain flexibility after departure), can you simply cancel the outbound of a roundtrip redemption and get half the miles and appropriate taxes back, or would you have to cancel the whole redemption and re-book?
You can't change a return booking into a oneway booking. But I am assuming that the OP knows this and that he currently has 2 oneways booked. In which case his post makes perfect sense and is something that I'd do.
In answer to the OPs ultimate question; no theres nothing that will happen if you miss a return leg of a redemption booking. This must happen many times a day, for innocent reasons such as lateness.