This is the video that was part of the decision to seek out training beyond the training I was doing with firearms.
You can't keep people 21 feet away. You stand in line at the grocery store, People pass you walking on the sidewalk or in parking lots. Other people are in the aisles at the store.
If someone is five feet away, engages you in a victim assessment exchange and then decides to pull a knife, you will never get a firearm drawn from concealment in time. It might as well be at home in the safe. The initial encounter is going to happen. If you can survive the initial attack and can turn/pass/throw/disrupt the attacker, then there may be a moment to draw and use your defensive firearm.
Dan Inosanto is an incredible martial artist. At 78 years old he continues to train and teach Eskrima, Silat, Muay Thai, Jeet Kune Do, and other martial arts. He is the aggressor in the room with the officers in the first part of the video.