I'm not an expert on match ups and stuff, but Shikamaru does have flash bombs as shown against Tayuya. Maybe it's possible he sets them off and possess all the mirrors while Haku is blinded? Only thing I don't know is it does keep Haku from moving, how would he land a final blow...
For now, I'll agree Haku wins. I just don't see how Shikamaru can land a final blow.