I feel like a broken record, but really, just call ebay buyer protection. They are VERY helpful actually and it takes 2 seconds. I only really suggest this, not that I dont want to answer you're question as I will, but as it's the easiest, best solution to get all the correct info and they will also note your account so in case a problem arises.
That said, if he opens a case and you shipped to the address you were suppose to ship, in the timeframe you were suppose to ship, you will win, BUT it is never a good thing to have a case open, even if it is decided in your favor (odd I know), but ebay likes sellers to resolve problems without a case. YOU STILL MAY GET NEGATIVE FEEDBACK, and there is nothing you can do about it unless the buyer threatens in a message that he will extort you for money/refund due to him leaving negative feedbck. He if just does it, oh well, tuff luck as that's his opinion of you not being a helpful seller.
This situation kind of sucks in general....depending how much it was and what your profit was you may decide to just be nice and split it or you can say sorry no can do. Totally up to you
I haven't been in the situation yet but if you win a case, they can't leave feedback. I think I read that somewhere.
I know that is not how it has been in the past.....unless things have chanced unless I see that in writing on ebay I would assume they still can.....as said best to call and ask