well basically how Mello said it was when he was a purple belt that one day this really chubby really un-athletic kid came in and rolled around. he was getting basically killed but wouldnt tap, (in the manner where he'd defend not just lay there without tapping). so after it he went straight to Carlson on his first day and was like "I'm gonna be one of your champions". and that was Wallid Ismael.
Mello also said durin the whole time he trained wit Wallid he never saw him tap