Yes, there is provably fair here in Bitcoin gambling land where you can check hashes to make sure casinos aren't changing numbers on you. Otherwise, I think it's up to the gambler to go with a site that has a proven reputation.
Why do bad odds imply a scam? It's not a smart gamble but it certainly doesn't make the lottery cheaters. They aren't rigging certain people to win.
What stops the ponzi operator or his friends from depositing and then paying themselves out? Just because there is a blockchain doesn't make it easy to follow abuse.
It will be interesting to see how the operator handles this situation. I don't think he will make up the amount lost and the fact that hes pushing forward with the 24hourponzi with higher limits without resolving the weekly one is bad news. There is a large scam in the works. You can quote this post at a later date when it happens.
Again there are many backdoors ... you proof is little comfort if the house bets too and wins more than what is fair. However there are much simpler ways for the gambling sites to cheat and we have seen many sites of all times lose tons of coins to hacking. I think it is a very safe bet that some of those hacks were inside jobs.
However, I digress. I'm also very interested in seeing how the operator handles this situation. If the pushes forward a 24hourponzi without resolving this one that be a horrible abuse of trust. Maybe enough to tip me in to the anti-Ponzi camp.