Yea. Online games are a b!tch. In my opinion, an online game can never go beyong beta testing, because there are always new ways that people find out how to scam/cheat/hack.
If you dont want to get scammed, make a shop in the market, so far nobody i know has been scammed that way.
(Watch, as soon as i say this someone will get all their stuff bought without getting any money LOL)
But back to the main subject, I honestly don't have the slightest idea of what he could have done. It doesnt make sense that he could have used artmoney, because the server now checks to make sure you have the amount of money before it finishes the trade. As someone said before me, the packet sending trick is supposed to be patched. So, it is possible he/she has found a new way of scamming that nobody else has thought of.
:bandit: