It's basic for Ninja to expect unexpected,especially for Madara who is not ninja,he is a god.
Well I think he should have been able to,they are universes apart from each other (in power level).
Madara is a god,his power is beyond everyones,expecially Zetsu's.
And he created him,Zetsu is his will,he controls him with his mind,and now all of the sudden he punches his arm through him.
I really don't know what was that for,Gai eight gate level coudnt penetrate through him with all his might,and now Zetsu can?