Great question, I wondered about that too. The paper is interesting, although I couldn't follow all the chemistry stuff:
It's licensed under Creative Commons for all to access and seems to be written by a great team. However, I searched for fire in the paper and there was no mention.
It looks like the spontaneous combustion of a Tesla in a parking garage in China was arson, but we had one crash a mile from my home and burst into flames, and it was intense. We're in the very center of Silicon Valley with sophisticated chemical fire fighting equipment, and the fire department said it was a real struggle.
Credit to Elon for making this advance so open, and also for letting the researchers go a different direction with battery tech than he has advocated for many years.