How about open-dating the ORD-SFO segment. Then when you pop up in SFO Cathay will have had no reason to cancel their segment(s). If it's an e-ticket I suppose the agent doing the check-in will be reminded by HAL that you didn't fly the previous segment and may or may not charge you $125 for your transgression. Under those circumstances I doubt that even CX would charge you, though.