In "The Exact Exposition of the Orthodox Faith", St. John Damascene writes that in assuming human Nature, the Logos freely assumed "unblameworthy passions, such as hunger, thirst, weariness, labor, tears, decay, shrinking from death, fear, agony with the bloody sweat, succor at the hands of Angels because of the weakness of nature, and other such like passions which belong by nature to every man" ("Exact Exposition of the Orthodox Faith" III.20, Patrologia Græca, Vol. XCIV ).
An Augustinian view of the Fall and Original Sin combined with the Roman Catholic view of the Immaculate Conception does not allow for this. If "Original Sin" and the consequences of the Fall were extinguished in the Virgin, then so were the passions to which they give rise. Therefore, if the Virgin was did not have the consequences of the Fall in her nature along with the passions which result from it, then Christ did not assume these passions- and He was therefore not "a man like us in all things except sin", and therefore, human nature is unredeemed.