That is quite the interesting question! I have never thought of that before. I suppose you just evacuate through the nearest door/exit just like any other situation.

This will probably dump you out onto the tarmac if you are out in the departure gate...so since the airport is a secured area, they'll probably just check your passport again and you'll be on your way. I doubt you'll ever find yourself in a situation where you'll be back INSIDE the country after you just left, but even then, I think in extenuating circumstances it's certainly an easy explanation (sorry, had to run out, there was a fire) when going back through exit immigration...

Also, just a general comment. The reason you were probably treated that way is that you had a very odd routing and they saw it, and had someone waiting for you so you wouldn't have to go through any hassle. The reason for this is probably that it's #1 very odd (and annoying!) to do international transits through MNL and #2 you were getting right back on the plane you just got off of...

I've found that most airline employees are familiar with the concept of mileage runs and will accommodate you so you accordingly since it's often a special situation.

Also, the most annoying thing about those GUM flights is that they take all of your bottled water and liquids away...so annoying if it's your first time (like it was for me) leaving from MNL on that particular route, and you just bought a coffee and some water for the stupid redeye. And in MNL in general the security LOVES to take your lighters away.

-IR