Originally Posted by
Repooc17
The purpose is to ensure only ticketed pax are admitted into the PL.
OP had a ticket and could prove who they were. If there is a purpose to requiring a passport, it's not this.
Can I ask how you are able to travel w/o a valid passport for an INTL itinerary?
Just to speculate: I'm assuming OP had someone bring the passport (e.g. from home, possibly by a family member traveling with) sometime between arriving at the PL and boarding the international flight.