Nobody takes it literally like that though, because at least in a better job market way too many people have that money.
If you want to tie it to a single scenario I'd say it's taken on a meaning more like 'I'll do what I want to you/your business/parking because I don't care about paying to sort it out if I'm sued'. Parking where I 'can't' & paying the 100x fine seems better to me than finding where I 'can' and paying the 1x ticket sort of thing. Not to say everyone's morals would have them act like that, but illustratively.
I get what you mean, but having enough not to work is the definition of FU money. It means you can just drop your things and leave when the boss demands you something you're not willing to do.