I suspect anyone interested will know immediately to whom I am referring, and a handful may know what put the subject into my head.
For the one or two people out there wondering, yes, I have a Certain Someone's books, have read them, and I am also studying Taika Oyata's RyuTe under a seventh dan who has been with the system for something like thirty years.
If you're wondering, no, what I have been taught and/or have seen in RyuTe is, I do not hesitate to say, nothing like a Certain Someone's kyusho.
There it is, for what it's worth. People wanting more of what I think about the subject are advised to search Openhand's blog for "kyusho" and "kyusho-jitsu" (or "kyusho-jutsu"--can't remember how he spells it). He says it better than I do anyhow.