There is wide recognition for the accomplishments of Jon Bluming, who was a protegee of the Great Mas Oyama. There are unique accounts from Bluming about his time in Japan and about the teachings of the legendary master. However, some of these accounts should put in perspective:

So I heard (from legit source) that at the time, just before their falling out, Oyama visited the Netherlands to straighten out a dispute with Bluming. During one of their meetings, Bluming was trying to negotiate a lower membership fee, which is normally due to the Honbu (head organisation) in Tokyo. Oyama rightfully, did not accept this, and at one point during their conversation, Oyama hit the steel top of a solid table, which was in the room, with his bare fist. He hit the steel top of the table so hard, that there was a big dent, which was visible to the shocked onlookers in the room. After that, Bluming gave in, and agreed to pay the membership fees that his organisation was due to the Honbu. Oyama was amicable in person, but he was not someone you could mess with in business. He was a legit badass and is an undisputed legend, period.