You have a right to raise your concerns, if you spot something that might cause problems in the future. One thing about Wetsuit is this, if there are concerns raised, he or she will address those concerns. Wetsuit will either explain it in detail or he will improve the system.
I've just heard from wetsuit and I've asked him to have a look at this. My personal view and understanding is that sort of manipulation wouldn't work because there's a nonce on the client side. The argument that the server seed could be changed is negated by the fact you could easily implement a script that checked that before and after each roll. I'm sure there are enough sceptics out that have tried to catch sites out and have failed because they don't actually cheat. It really wouldn't be worth it, the site's reputation is worth far more than any individual bet.
Thanks for communicating this to Wetsuit.
If you look at the steps mentioned carefully. You can see that no matter what the client sends, the server can break the promise of which hash to use and the only way to catch is as you mentioned, or bots. I'm still not making any accusations. I just want to point it out that this can be as real as it gets and is currently extremely hard to verify this by any normal person.
I know FreeBitco has a huge reputation, but it also has a huge userbase, everyone is claiming 'free money' by the hour. If you take out most of the last 3 free-game prizes, statistically the server will end up paying ~7.34 times less. I'm just pointing out there is an incentive to cheat and the system allows it to make it easier to hide.