I think you're spot on here and I'm really not disagreeing with you, in fact, I think we're quite on the same page! I'm doing a poor job articulating my comment. In Asia, when I've been OPUP'd, it is usually at the gate and it's been a surprise. "Mr. JSmith50, please report to the counter..." type of announcement that has led to the production of a new BP. This is one of the only times that I recall having been OPUP'd that it occurred at the time of check-in, in a different city. To me, it would have made much more sense if on check-in at MNL, they had OPUP'd me for that leg and not the nextor if they had called me over in NGO to provide a new BP but instead it seemed more formalized that it happened at checkin. Don't get me wrong, I'm always thrilled to get OPUP'd on an international flight and don't and won't ask why, just thought the logistics were interesting. This suggests to me that DL has the ability to OPUP anyone at any time, almost like domestic UG's at medallion windows which we know very clearly do not happen on intl flights.