I think a way that these kinds of scams can be prevented in the future is to announce the payment addresses publicly on this thread
Doubt people will bother to check. Addresses are just random to most people. What they really need to check is who they're actually sending money to, but no amount of precautions put in place wont stop some people from getting scammed.
The person in question had at least attempted to advertise on the forum before (I don't think he won), so in theory he would have previously seen theymos publicly providing the payment addresses and when this didn't happen when he "won" he should have noticed that something was 'off'