UPDATE – 9/11, 9:45 AM: Thanks to the commenter below, Mr. Orange, who posted a link from RFE/RL explaining Dokku Umarov’s inconsistency with regard to the position of the Emir of the Caucasus Emirate. Here is the important part:
Umarov explains that at a meeting of Chechnya-based fighters and commanders, he was subjected by rank-and-file fighters and the two Chechnya-based emirs present to a barrage of criticism. He said they specifically reproached him for having claimed responsibility for the most recent “special operation” in Russia, meaning the Moscow subway bombings in March, even though those same emirs and fighters had upbraided him one year earlier for not taking responsibility for other such operations elsewhere in Russia. The fighters also accused him of not doing enough in terms of securing provisions and arms supplies. Umarov acknowledges that the latter criticisms were justified.
Umarov then says that in light of that criticism, he “sincerely” proposed to step down as commander, providing that the commanders of the other fighting units approved that decision. A video address announcing his decision to step down was then prepared for distribution, and entrusted to Umarov’s newly appointed deputy, Aslambek Vadalov.
Vadalov, however, violated the oral agreement between them and prepared additional video footage in which other emirs, including Khusein Gakayev and the Arab Mukhannad, presented Umarov’s resignation as a done deed and expressed approval of Umarov’s imputed request to swear loyalty to Vadalov as his chosen successor.
In light of that move, Umarov explained, he decided that he should not relinquish his duties as commander — hence the vide clip posted just days later in which he denounces the original video as a fabrication.
NOTE: This video was originally recorded on August 30. One of the online jihādīs thinks this video deals with the controversies of the past summer, but since it is in Russian neither him nor I can confirm this. But, if you want to know more about what occurred read what I wrote about it previously (see here, here, here, and here).