Legal analysis of article on "mass riots" in Criminal Code of Russian Federation

Today, on 21st of February 2014 the verdict on so-called "Bolotnaya case" was partly announced in Moscow. Defendants of this case are accused for organizing/participating in mass riots, meaning the events of 6th May 2012 on Bolotnaya square in Moscow.
At the same time, journalists, activists and experts reported on multiple violation of trial procedures, and there is still a lot of questions to the eye witnesses of policemen and other authorities.
Here we present the part of Report by the International Expert Commission for evaluation of May 6 2012 events on Bolotnaya sq. in Moscow. 
This part is dedicated to legal analysis of article on "mass riots" of the Russian Criminal Code and on the fact that the May 6 2012 events may not be qualified as "mass riots" due to the Russian legislation itself.
This legal analysis will be very useful for those interested in human rights situation in the modern Russia and the limits of the law interpretation.