Zoro wasnt using the extend of his haki like in this panel:
If law is able to move this while Zoro is fighting Law. I ll admitt that sure, Zoro haki aint that special but if that is not the case drop your dam headcanon
From your panel only once Zoro got moved and that happen for 2 reasons Zoro wasnt focusing on Law (so he doesnt see him as an enemy and because Zoro wasnt really using haki check the blade)