As you know, at that time, OpenCL just came to the market as a new parallel computing language and framework, and the demo showed one of its power features: scaling. The referred video demonstrates how OpenCL can be used to scale an application without making changes to the application. I think, the application was modified to showcase the demo, not intended to release the modified software.
I converted only pressure and air movement to opencl(3-5 x speedup) but I got other work so I couldn't complete but it scaled well with gpu. Particle calculations would be harder since they all update sequentially such that a particle could have different movement than a neighbour but in big picture they look like a real fluid.