As mentioned in the messages on BCM, I have opened this thread for information, so I will start with my own

I did two trades with the member:

ID:2600    BMBTC/PPUSD    24.9899 USD per BTC     10.0000BTC
ID:2574    BMBTC/PPUSD    29.9899 USD per BTC    11.0800BTC    

Total: 583 USD.

A while after the trades, the buyer filed a dispute on paypal, and even though I did my best to stop it, the transactions were reversed.

I have sent a message via the Paypal help center to at least try to get some information about the transactions, and the dispute-resolution.