Fraud definitely exists, but paypal should give more leeway to customers they know aren't fraud. Yes, this customer could, all of a sudden, turn into a fraudster, but there has to be a way to combat that without being so openly hostile at the beginning to a customer in good standing.
Not in my case. I bought an iPod over eBay a few years back. It was delivered faulty. I chatted with seller who said send it back. I told him I would when I "got back", which I did. Sent it registered. The guy stopped answering mail when he got the device. His reputation started to plummet very quickly, mine was 100%.
PayPal refused to investigate because I notified them too late (about 6 weeks after purchase) despite emails, faulty item delivered and acknowledged.
PayPal is a scam and I will never trust their buyer protection again.