According to Sherdog, he has a record of 11-0. 10 of those wins were submission wins over relative nobodies except for an over-the-hill Sakuraba who was on a losing streak. One of those losses was to Jason Miller, who does NOT train in the gi, and he won with the same submission that this guy also beat Sakuraba with: the arm-triangle. His last fight was his UFC debut against a mediocre fighter named David Mitchell who he did NOT submit and Mitchell was promptly released after this being his 4th loss out of 5 fights in the UFC.
Not a convincing argument for the gi in my opinion.