The rule in Florida is, you must be in fear for your (or someone's) life.I think the basic premise behind CC training and action is that if the other person has not pulled a gun and or shot already or directly confronted someone with another potentially lethal weapon your gun stays in its holster.
Bad guys waving his/their gun/guns around and firing shots or has one to someone's head or has a knife or other such item to someone's throat then it's probably okay to unholster yours and consider your options on taking defensive actions.
If no obvious life threating actions have taken place your gun stays where it belongs.
It's not a hard concept to follow for any sane rational person of which the vast vast majority of CC persons are.
A 300lb linebacker holding you by the throat is considered reason enough. You don't have to wait for him to draw a weapon.