When we look at defensive force, what is justifiable can depend on a great many things. First and foremost, it depends on the law. What does your state law say about self defense? When is it legal? Second, are their prior court cases that clarify how the law is applied in the actual courtroom? Finally, public perception can play a role in prosecution of a case.
When looking at our current world, there are some locations where public perception may skew to one side or the other. With some of the coastal cities, we are seeing a lack of prosecution of protesters/rioters, but more prosecution of those that fight with the protesters. With this mentality, will you potentially be prosecuted even if you use defensive force properly under the law? If it appears to have been outside the law, or can even be argued as such, you may end up in a lengthy court battle with a prosecutor that is trying to "serve the citizens" by following public opinion.
Also consider what is a legal use of force when it comes to unarmed defense. If the police use of force now considers neck restraints (chokes) to be lethal force rather than a lower level of force, wouldn't it stand to reason that using it in self defense may end up under the same scrutiny?
It is important to apply your critical thinking skills to your own defense. Look at the world around you and ask "what would the general public say about me if i did X?" or "what stance would the mayor and city council take if I were to use force in this situation?" Thinking ahead of time can make you smarter and more cautious in our current anti-establishment world.