I was curious too, so went hunting online and found two interesting pieces. The first is some commentary from 2009 when Rittenberg apparently spoke at the Yale Club in Beijing:

http://www.newyorker.com/online/blogs/evanosnos/2009/10/sidney-rittenberg.html

Also an article which touches on 1989, with comparisons to the cultural revolution:

http://newsgroups.derkeiler.com/Archive/Soc/soc.culture.china/2005-11/msg00603.html

Interesting stuff.