Ugh yeah that's why you tell them it's been put out.

"Wait, did they just say batteries can start fires?"

Bold of you to assume they'll continue to listen after the keyword "fire". In the worst case, they'll actively doubt you and, worse, start doing so in a very public way ("they're just claiming the fire is out").

And yes this shit has happened in the past. Panicked people are uncontrollable and in a critical situation, priority #1 is to avoid panic to rise at all costs because panicked people can turn a critical situation into outright disaster.

- "panicking themselves so hard they're going to behave completely irrationally (like attempting to rip open the emergency doors which IS possible at low enough altitudes)"

The Denver airport fire this month was an object lesson. A panicking mob apparently ignored instructions and went out the wrong emergency exit door, onto the airplane wing, where they stood over the flaming jet-fuel smoke with no way down.

(The other doors had slides).

Yeah. Right there on the safety card--note whether there's fire outside an exit before using it.

Yeah, I can like individuals, but not crowds.

Crowds can do dumb shit in a self reinforcing loop.