Posted By:
warshawlawI generally mention it and offer additional scans and information if someone is interested. Never had a return yet.
On the buying end, however, things have not been so sanguine. I recently had to return a very rare card (T224 Fitzsimmons) that I really wanted and that I got for a decent price at auction because of back writing. The dealer (who has been in the game for decades) then gave me the lame excuse that he doesn't really know how to grade cards. Needless to say, his current email auction notices are assigned to AOL's spamblocker whenever they come in.
I find that when a mistake is made with the back, a seller will frequently agree to give you some cash back. Scott Gaynor is one with whom I had that sort of positive experience. He missed a small crease on the back of an N174 Tug Wilson Gypsy Queen boxing card and we worked out a partial refund to cover it, since I wanted to keep the card.