google/nsa/cia/mi6/dgse, none of these are 100% secured, even pentagon isn't, this is why they issued a bounty of 40k$, and they said that a lot of security breaches was found.
Now bitdice is a gambling website, they issued a lot of efforts in the security of the platform, but it has breaches for sure. Now who will be smart enough to find "and" to exploit them.
Well you stated your idea, now you can do and exploit them. Every site really have a vulnerable part which may crumble down, though that why they are enhancing their securities. You don't need to exploit them really, you just need to trust them.
by exploit i mean using the break to harm the platform or the users.
I won't, because i can't, i am not a professional hacker, i just know some security tricks, and as far as i can see, they are respecting the basic security principles advised by many programers. And this, just a few websites do it.
But you can be sure that as soon as find something i will report it, you won't even see it in the forum unless they don't correct it.