If he's smart, he would realize that Hashi isn't the only enemy
Chapter 573 was where we saw the sweat/rain drop on Obito. With this link, http://narutobase.net/forums/showthread.php?t=151367, I agree with the poster that said Obito was using the rain drop as an excuse and he really was sweating.
We did see Madara look nervous when Lee attacked him.
There have been times where Naruto himself has shown to be surprised/nervous/scared/worried about the power his enemies have.
Does anyone else Edo Madara wish he'd would show a nervous look at Naruto? If he's smart, he would realize that Hashi isn't the only enemy that could take him on/defeat him.