Conflicting copyright information on Coursera

The copyright notice for the lecture notes on Coursera says you “may not use or distribute these slides for commercial purposes.” However, the same notice also mentions and links to the Creative Commons Attribution-ShareAlike 2.0 Generic license, which does allow commercial use. Can we get some clarification on what is the intended license?

It is my understanding that the presence of a free license would override any non-commercial clause, and that such a license would be irrevocable, but I think it’s important to respect the author’s wishes.