The safest way to win from gambling is to be the house or invest in the house.
Though there is a bigger chance of winning when you are an investor, there are still situation when your investment gone smaller because someone played and win big in the site that you have invested your coins in, so still not safe..
It depends on the size of the investment and how would it matter to you if you never get that back.There is nothing that can prove that the owner himself was gambling with an alt account and winning most of it by know the server seed.I think there was a similar case with MD.It's risking or gambling in the end.