Was that ever actually confirmed? Or was it just something he said?
Well, all things we don't see with with our own eyes leave us only with words from the others anyway. So it's up to each one to believe or not.
Personally, I watched the fight live and I was crazy about Vitor not using his hands and I posted about that in real time, if I remember well. I don't have a reason not to believe in his word for this particular issue.
Actually he broke his hand before the TUF finale against Wand (UFC 147)and apparently, the healing process was not good.