If manslaughter is defined as an action that leads to death after the actor disregards a risk that the action will cause death, that action can be justified by self defense. It may not result in a manslaughter charge or conviction, but the elements of the crime are there. Think of the elements as the definition. A thing is logically indistinguishable from its definition.
I'm glad you got that off your chest (it is a pet peeve of mine too). The fact that you think you might be teaching me this concept for the first time is amusing. I have worked cases as a criminal investigator in twelve states, on a variety of cases and with a caliber of prosecutor that I dare say favorably compares to what you've done. This ain't CJ 101, and you ain't the professor.
My basic point is reiterated at the beginning of this post. I think we are talking past each other, and my initial contribution to this conversation wasn't even that relevant to the thread to begin with.