It's also that if a Lithium battery catches fire, it's not going to be stoppable by a common extinguisher. The only thing you can really do is put a shield around the fire, or drop a tungsten dome around it and pray it doesn't fly off.
Li-ion battery fires are commonly fought with water.
The case we primarily discussed was an EV fire on the car deck of a ro-ro ferry.
And the conclusion from the paper is important:
"Using water mist resulted in a temporarily increased production rate of HF but the application of water mist had no significant effect on the total amount of released HF."
Essentially, our conclusion was don't touch it, if you have to then cool flammable things in the vicinity and as a last resort if things are about to spiral out of control put water on it.
The only other thing would be an electric component overheating or shorting, but that would cause a small explosion rather than a continuous fire.