Someone gets a lucky run and it's a conspiracy. It's not impossible (never say never) it can exploited but we can't rule out that the RNG ends up favoring the odd person from time to time. As Dawnseeker used to say random is random.

I played Evony for nearly 4 years and the Wheel of (Mis)Fortune is pretty much the same as the Casino here. There are differences obviously but the basic software is similar. Evony tended to be an exploiters paradise, if there was a bug that gave players a huge advantage then it was uncovered to an extent it never failed to surprise the devs. However, never once did a bug arise that 'fixed' the wheel. So the chances are, its a very lucky run and try not think that everyone is cheating just because they do well or get lucky.

That said, report those who you suspect of cheating to Customer Support and don't post it on the forum.