Originally Posted by
anabolism
As I wrote, this is not likely. However, in the unlikely event an airline did go after someone for no-showing on the last leg, The appropriate penalty would be the no-show fee of $125. (Recalculating the fare as the sum of the fares for the flown segments is the process for a cancellation and refund of a partially flown itinerary.)
Maybe. If your ticket still ends in the continent of origin, you have satisfied the rules for eligibility for the fare, and there should be no penalty. However, if your last flight is intercontinental, it's possible that you did not fulfill the fare's requirements, and, based on what you actually flew, may have been ineligible for the fare to start with. In that case, it seems to me that since you're not eligible for the xONEx fare, what's the alternative?