Who did Dean earn his blackbelt under?
Couldn't find anything official. BJJ.ORG, which had all the lineages, has merged with on the mat, but I did a search of that site and came up empty.
Dean did most of his BJJ training under Fabio Santos (7th Degree BB under Rickson) in San Diego.
He also trained in Brazil for awhile, and could've gotten it from someone down there.
I'm guessing he got it from Santos.