That's the word according to the UG:
Chael had/has a broken arm.
Courtesy of Nick "The Goat" Thompson who is a UFC veteran and former Bodog WW champion. It's not April, and I don't see why he would have a reason to lie. I suppose that kinda of explains his performance in the fight. Filho wasn't interested in engaging in the fight, and Sonnen wasn't interested in finishing Filho either. The whole fight consisted of Filho either laying on his back doing the butt scoop eating weak leg kicks, or both fighters standing with Sonnen flicking a weak jab out. If this is indeed true, I give Sonnen madd props.