[RedDevil]

The video shows pure lithium, that's not what is inside the battery.
Pure sodium reacts the same, but for instance salt (sodium chloride) is fairly safe. It is not the raw elements but what they are attached to that make up the properties. The whole chemistry so to speak.

But Lithium Ion has weaknesses; it can overheat when overcharged or exposed to extreme heat or discharging, like what might happen if you cut open the battery pack and short some cells, what apparently is what happened in the stricken Model S.
Had it used LiFePO4 cells that would not have happened. Those cells won't burn even when mistreated.

Good for you that you could save your car from destruction by fire 3 times, If you ran petrol instead of diesel or if the tank were torn open and that caught fire, to compare it to what happened to the Model S, you would not have been able to.

That an EV fire should not be put out with water is mainly because of the electricity, not the chemistry of the battery. The power should cut off in an accident, but when the pack itself gets damaged really badly there is nothing to fall back on. Better be safe and use only extinguishers suited for electrical fires.

Petrol fires don't get easily put out by water too. The water tends to sink below the petrol, making that spread faster. It may even cause an explosion when it hits something hot; the steam stirs up the liquid petrol, etc. That is why car fire extinguishers often use powder; to trap all fluids and absorb the heat giving off non-burnable gases.

I've seen a car burn out during the rush hour when I was young. The fire started at the engine bay but spread all over in about 15 seconds, and the gas tank exploded about 30 seconds later in a gigantic fireball. The heat from that was immense. Several people who watched the incident from about a 15 meter distance got first and second degree burns. Never mind the damage to other cars, trees, lamp posts and houses nearby.
No battery can create that much havoc.