the guy might be talking about reversing transactions. I probably get two actual customer initiated chargebacks a year, but maybe two or three times a month, paypal initiates an "investigation" which usually results in the transaction being reversed (though I often still get stuck paying the fees)
There is really no transparency, and from my point of view, they look pretty random, so it would be pretty frustrating, but it's usually on a $12-$20 transaction, so it's hard to get too worked up about it; they /are/ a bank, and one expects to get nickle and dimed when dealing with banks.
I email the customer and they make other arrangements to pay me (or sometimes they just re-send the payment and it goes through) so I'm only out the fees, but I have more leverage than the original poster, as, well, I provide a service that I need to keep providing, while the parent sounds like they provide a product, and once the user downloads it, they have no leverage.
If I was losing the whole amount, I could see how it'd be pretty frustrating, and how it would look like paypal is just stealing your money.