IIRC there's an episode of the .NET Rocks podcast where games in F# (roughly oCaml for .NET) is being used as a backend for these gaming systems. http://www.dotnetrocks.com/default.aspx?showNum=846

That bug probably wouldn't have existed if the code had been written in a functional language where state management was an inherent part of the whole deal.

Then again, some of these video poker systems look like a glorified Sega Genesis, and probably run under similar hardware, too.