A question about the Big Bang?

First, I want to make it clear I am not trying to discredit anything, I'm just trying to understand the physics of it. I'm watching this thing on Science Channel and one of the scientists says the laws of physics allow for something to come out of nothing; he is talking about the Big Bang. My question is, how does this apply to the Big Bang when before the Big Bang the laws of physics (or physical laws of the universe) didn't exist? If there is nothing there are no physical laws yet so what do the laws of physics have to do with it? Could someone with more education on physics and thermodynamics please help clarify this? Again, I'm not trying to make an argument against the Big Bang, I'm just trying to get more about the theory.