I simply do not see how the aviation industry can afford to implement CVRM.
The logistics of being able to capture these "rogue" pilots using analysis of the last two hours of any given flight would require massess of data being processed. Then, as someone has rightly pointed out, the correct contextual meaning of even small samples of voice data could take weeks to determine by well trained specialists. Even then the result can be disputed.
With pilots coming from all over the world, you had also better make sure that the speciallists are multi lingual for the occasions that they break the sterile cockpit in their (non English) mother tongue.