Wait a minute. What's your source for that? Was it a fan site or Wikipedia???[
Mix of that and his personal statements and interviews...
Started at 12, left formal classes for MMA around 17,
But hey, technically hes a 5th dan

Regardless of his rank, when he says hes using TKD, Its definitely tkds method and not karate or MT, im gonna call it what it is
This is part of why i love the guy so much, its a VERY difficult thing to do, blending such majorly different styles/techs without sacrificing any form or tech of the root style. Its just natural find this inbetween with techs, and he makes a point to not do that.
To me, THATS mma in its purest form and just beyond awesome to see