Fixing software with documentation at Harvard

Much has been made of Harvard School of Law's online course on copyright law. The course, given by Professor William Fisher, covers a range of topics related to the theory and application of copyright law in the U.S. and other countries. The course is limited to 500 attendees, participating in groups of 25, giving a small-class feel to a massive open online course.
Registration closed on January 3. As a result, we are told to ignore the big registration button on the course page.

This is what we call Fix It in Documentation. The way that the HTML page is stitched together, the registration button is one component while the course description below is another. It works well until it doesn't. Apparently, there isn't a way to disable or otherwise change the display once the registration period has passed. So, two sentences in red text tell you that they couldn't change the button and that you can't do what the button says you can do.