If anyone's interested in the quantum mechanics, the reason why we can get something from nothing there is that particles are not just hard spheres moving around, they exist mathematically as a probability distribution - saying where they are most likely to be at one time. You can't pin down a particle to an exact location and measure everything about it.
So when we measure vacuum and say 'there is nothing there', that is only an average, or likely, measurement of it. There might be something there, our measurement didn't rule it out completely. So sometimes when we look, there is something there. You can't even say that it was definitely created there, it might have just teleported in from somewhere else. The best example is that a particle in a well, where the walls require X energy to climb over, can sometimes get out of it with less than X energy because its position is uncertain so it MIGHT actually be outside the well. And if we wait long enough that will turn out to be true.
The universe only has to obey its laws on average.
This is different to just saying what we don't know what happens. We have very good laws saying what is allowed at what probability, and very precise experiments showing us that quantum mechanics is a good description of the universe.
