I don't think Segal is claiming he trained with O'Sensei:
Q: And your experience with 0-sensei?
Sensei: I have very little experience with 0-sensei. I was able to see him several times. I've seen him speak. I was very close to his spiritual teachers and I still am. I think I was the only white person to ever go exactly in the footsteps of 0-sensei in terms'of his mystical training. I became a priest in O'moto Kyo and went to all the aesthetic training with the priest that 0-sensei was raised with. I never really knew him. I never got to butt heads with him on the mat or was thrown around by him or anything else.