PayPal holding funds

I recently sold tickets on ebay. In the item description, I clearly stated that the buyer would need to pick the tickets up at will-call (auction ended on a Saturday afternoon for a game Sunday at noon, so obviously shipping the tickets to his address wouldn't work. Buyer paid for the tickets, but later claimed he didn't pick them up and wanted a refund. I told him no, and he filed a PayPal claim. I called the ticket office and they confirmed that the tickets were left at will-call for the buyer but that they were not picked up. The reason the buyer gave for not picking up the tickets was that he received an email from me which led him to believe that the tickets wouldn't be available for pickup. I never sent such an email.

My concern is that I have heard that PayPal often finds in favor of the buyer if the item isn't shipped to the buyer's physical address. If this is true, aren't they really just an escrow service? Do I have a case against PayPal for withholding funds?