How does passenger unloading order prevent plane tipping? This answer to the question about an emergency landing very early in a trans-continental flight indicated that the fuel in the aft auxiliary tanks could cause the plane to tip on its tail if the passengers weren't unloaded carefully. The cabin crew seems to have kept everyone calm and orderly, and they deplaned with no further incident.

My question is how did the orderly disembarkation prevent the plane from tipping?

These are the thoughts that ran through my head as I read the story:


Were the pilots busy moving fuel out of those aft tanks while the pax were deplaning?


If so would they have started the rebalancing as soon as the firefighters cleared the plane to move? 
Would that have taken the hour it took to get the plane to a gate for them to shift all the fuel? 

What else would be involved?
If the fuel in the tail would cause the plane to tip, unloading the pax slowly would still leave it with an aft CG, and it would still tip once the critical number of people were off.
Apparently, there have been a number of incidents with 'tail tipping' in case of Boeing 737-900s and 900ERs. In these situations, the plane 'tipping' on its tail can be prevented by two methods:


Unloading the passengers starting from rear to front.
Unloading the (baggage from) aft cargo hold before passengers were allowed off the aircraft. 


There is also some indication that the 737-900s are loaded in the front rows (1-17) first followed by aft rows, while the unloading takes place in the opposite way.