! No, it wasn't a true emergency, and like GUWonder wrote, I judged that it wouldn't matter. The main point is that there exists a provision by which US dual nationals can travel on their second passport provided it has an ESTA associated with it. And, it's probably true that they could even travel on an expired US passport if the airline would let them, but using their second passport with an ESTA seems like the most painless way to go (and best way to avoid a secondary). There's no point in arguing the fine points like "Was it a true emergency?" The information that GUWonder provided on this forum saved me from canceling the trip and losing thousands of dollars. By posting my experience, I'm simply trying to pay it forward and help others who find themselves in the same situation. As always, your mileage might vary.