Do un-blockable hits count toward the achievement?

For the Point Counter-Point achievement you have to complete the Deathstroke battle without missing a single counter. But some of Deathstroke's attacks I cannot block no matter how hard I try. No counter icon comes up, and he hits me no matter what and does damage.

So do these hits count toward the achievement? Do I only have to counter the hits that are possible to counter, or am I not allowed to take any damage at all?