Appraisal Sq/Ft 10% less than listed

[Matthew M.]

Wasn't expecting this to come up.  The house still appraised for over sale price but I was wondering if this could be used as a negotiation moment or am I SOL?  10% is a decent amount to be off by.  

I know, it's a long shot, since typically appraisal contingency only covers a situation where the appraisal is lower than the sale price.  I am still happy with the price even with a smaller than expected sq/ft.