Kimo started as a TKD guy, than as a jiu jitsu guy. He got his black belt in bjj a while ago under John Lewis. Kimo also fights in K-1. He fought sapp (lost,) and lost another fight.
Its really nothing special to Take tank down, since Tank dosn't train at all. By the way Kimo is fighting Ken Shamrock at ufc 48.
Thought I would be a bit pedantic here. If Kimo studies freestyle surely that would incorperate jujitsu moves anyway, why the differentiation. Freestyle recognises no boundaries, seems a little contradictory. Sounds like he is doing Mixed Martial arts to me. Whole different thing.