Attach a debugger and find out? At the end of the day, all closed source software is a black box, wether it's Acknex, Unity or Rayne.
The question is; Do you really need to know what's going on under the hood? If it were open source, would you take the time to verify that it does what you want it to? I have read my fair share of open source projects, sometimes because I was curious, sometimes because the documentation was awful, sometimes a mix of the two; Big systems make no effort in being easily accessible, and following code paths isn't as straight forward as it seems when you are familiar with the project. It takes time and effort to get startet with a third party code base, and ultimately, do you really care that much about it?

Not grumpy, just trying to be realistic. I know you Pad, and I know that you like to dig in other code bases for fun and profit, and I certainly see the appeal of it. So yeah, no idea where I'm getting at right now, maybe I should just go to bed.