A fun thing to think about with all these questions and speculations, is the fact that I don't think there are many casino owners that knows this either. Or the people who works there. They know their own area and what they have been hired to do, and nothing more.
In the end it all comes down to trust and nothing else.
You could explain to me for several weeks and I still wouldn't get it, and neither would most players.
How come a few of us do trust casinos even though we don't know everything? Well, we just have to or we will have to find something else to do.
Even if you get your mathematical explanation, what will you do with it? Play more or question it anyway?
Also it seems to be different depending on what Software it is, so you'll need more explanations.
You need to know how the games are tested. You need to know so much that you probably won't have time to play
Just some thoughts from me since the discussion seems to continue