It sure sounds like it:
"The last man to own a victory over UFC Middleweight Champion Anderson Silva, Japan's Yushin 'Thunder' Okami has won six out of seven UFC fights, putting him firmly in line for a rematch with the champ. At UFC 82 on March 1st, Okami may have been at his most impressive as he knocked out former UFC champion Evan Tanner in the second round."
The blurb above is for an auction in which the gloves Okami wore against Tanner are up on the block. It reveals that Okami did indeed break his hand against Tanner because the gloves will be signed "with his left hand since he broke his right hand during the fight."
Here's how the first fight went down for those interested:
(Thanks to MMAmania.com reader "Toga" for the assist.)