@Mahatma Kote
At sea-level pressure or lower it can only harm by displacing normal air completely and so eliminating the oxygen.
Precisely.
I am not talking of a plane that has depressurized, I am talking about a plane with normal pressurization, somewhat a little higher than sea-level.
If such quantities as shown in the Mexican pool example were liberated, then this nitrogen would rarefy oxygen. It could be another oxygen-scavenging gas than nitrogen (but we'd need a chemist to tell us which).
If the liberation of the gas was slow and not due to explosion, but due to damage to containers, and if the placement of the nitrogen allowed it to seep to cabin and cockpit through defective venting systems (air conditioning, pressure differentials between different parts of the aircraft), then one could posit that there would be a slow hypoxia onset for all living things in the plane.
That theory of slow-setting hypoxia, where I put forward that such damage to nitrogen (or other similar gas) cylinders may have been caused by a lithium battery fire (although it could be something else I suppose), is the simplest that takes care of all aspects of the flight, the behavior of the pilots and the end result.
Ohoh, I've been mod-ded too!!! Better quickly save the interesting posts before they disappear...