I know that shibumi has contributed years of service to the caving community. I am only one person but have to say that the amount of time and effort that he has put in to this community gives him some ground to stand on. I am one of the people that has learned vertical work from his teachings as I know there are many many others.
I would also have to say that there are many people here that would be considered the authority on the matter of caving and vertical work. Explaining their experience is not going on about how great they are it is simply giving base for those that may not know.
( I have always found southpark funny )