A few months ago, I had my first RWAP  (I posted about it here) where the receiver reported the book "Damaged by Sender" and asked for a credit back, even though she admitted in her PM that she'd torn the book herself opening my "Over-taped" package.  I declined to return the credit.  Now I was just checking my Tranaction Archive and see that the request is still listed as "unresolved."   

What does this mean to me, the sender?  Anything?  I'm not really worried about it, since it's the only RWAP I have.  I'm just curious. 

It doesn't mean much unless you develop a pattern of people marking your books RWP. Then they look at your overall record.  Also they can see the messages attached to the request and make a judgement call on that.  The main thing is that you responded politely and didn't harass the requestor.  If you never responded or confessed to wrong doing and still refused a refund then it would have a bigger impact.