He's correct about the first thing you understand when you're facing an attacker who has a blade (and you can't run away), you're going to get cut. But when you're well trained in defense v. blades (thus you'll know offense too, btw), you decide where you're not going to get cut. So there's no need to panic.
I realized years ago, after more than two decades of training, that the scenarios I was designing were increasingly unlikely to occur in even two of my lifetimes. And being attacked by a guy with a knife is even more probable than being attacked by a guy with a gun, and both are far less probable than being attacked by a guy with only fists. .
This instant escalation to deadly force in every crisis in the US is pathetic and a form of mental illness.