Asking for tax $ money

[Tony Castronovo]

I sold a house last year. Just got an email from the title company, copying the buyer to ask me to pay about $500 directly to the buyer. Apparently, when the buyer compared actual taxes she paid, with the way it was projected at closing there was a sizable difference. Am I obligated to pay the buyer? I can't see what recourse there is. And if I did pay, how can I show proof that these were taxes so that I can work into my deductions when preparing my return?