FIRE or not, I've left every single job in a snap decision after "one bad day". Like pp above, I set extremely strict boundaries with the people who hire me, and if they violate those boundaries, I'm out. Now, my boundaries are eminently reasonable, so it's a tall order to cross them, but some employers lose their minds sometimes and do stupid shit that can't be undone, and if they do, I'm out. No exception.
How bold this is really depends on how easy it is to find comparable level work. In my case, even if I were out of work for years, it's laughably easy to find a new job. As in, with a single phone call, I could have at least a half dozen jobs lined up within 24-72hrs. I also don't have to worry about ageism.
So for me, leaving a job is virtually inconsequential to my future career options, so yeah, one bad day is enough to trigger bailing.