Open Source and the Law

Slashdot has a large discussion of a very small article on a number of Florida judges who are disregarding the results of breathalizer tests because the manufacturer refuses to disclose the source code. It's an interesting idea. I think there may be other areas (black box voting systems) where this is more appropriate, but I like the general principle. In this particular situation, I wonder if there aren't other ways that the accuracy and reliability of the devices could be established, and whether that would satisfy the basic inquiry. A little more detail in the article would have been nice...