Conversations regarding the legal consequences of employing martial arts techniques off the mat are rare, if had at all. Usually these conversations are had after an incident has already occurred, to either chastise the student for using said techniques on the street or as a cautionary tale to other students.
The more knowledge you obtain, especially in the case of professional fighters and high-ranking belts, the more scrutiny your actions are under when used in a non-sanctioned event. For example, a professional fighter getting into a simple assault and battery, those charges could increase to aggravated battery with a deadly weapon. The deadly weapons in question are the hands and feet of the fighter. This isn’t such a crazy notion to people who understand how skilled fighters can use their precision and expertise to devastate.
Often people fail to realize that walking away from a bad situation has nothing to do with weakness, but rather everything to do with strength. We walk away not because we want others to realize our worth and value, but because we realize our own.
It should be the student’s instructors responsibility to inform their students of their respective states law on justifiable use of physical force in a self-defense situation.
I would be remiss to not inform you that I am not a lawyer (yet!) but rather a law student and BJJ enthusiast. Proper counsel should definitely be consulted on this issue and how it pertains to every martial arts school and instructor wherein.