When I saw what the page was supposed to do, (first five and last five sets displayed in random order) the first thing I thought was, "Man, I hope they tested the fool out of that or someone will make a fool out of them."
Looks like there wasn't quite enough testing. That said, I don't think that anyone could argue that the bug was damaging. No one browser was ever left out or in the same position.
Doing the Microsoft Shuffle