Earlier quoted context omitted.
From first hand experience, PayPal has always sided with the buyer. I've definitely run into similar situations where I was forced to give a refund or face losing the item / PayPal withdrawing the money from my bank account even though I stated that no refunds were allowed on my eBay listing. PayPal told me that it meant (crap) and there was no such thing as a no refund policy.
If that's the case, I can't wait to go buy a bunch of music CDs and software on Ebay to pay with PayPal, only so that I can pirate them and then get my money back. /sarcasm What a shortsighted policy, but then again PayPal has never been known for their agreeable business decisions...
Credit card companies work similarly. I've known people who've racked up huge bar tabs and then called their card in stolen.
In reality, most business is run on the honour system like this. You can dine and dash, but only until the wait staff start recognizing you.