What authority did Prince Vassili Dolgorukov (Imperial court marshal) have over Kerensky and the Bolsheviks?

As a marshal of the FORMER Tsar I would think none, but in the 2000 film "The Romanovs: An Imperial Family" the Prince seems to command one particular soldier, Dorofyev, and also is shown at different times corresponding with, negotiating with, and giving AND taking orders to/from the Ural Soviet (the local government of the district where the Romanovs were held captive). IF YOU CANT SPEAK RUSSIAN TURN ON CAPTIONS IN THIS CLIP: http://www.youtube.com/watch?v=C1OzyYwj_yk&feature=related at 2:40 Dolgorukov seems terrified of the Bolshevik soldier behind him and follows orders. Then at 3:30 he is corresponding with the local Bolshevik soviet government. However, at 6:55 when soldier Dorofyev and the Tsarevich Alexei Romanov are about to get into a fight, Dolgorukov orders the soldier to stop it, and report to "the Commandant". So who exactly is this guy (Wikipedia has nothing) and how did he maintain some control over Bolshevik soldiers while also taking orders from them? Where does his authority come from? He is killed at the end of the movie along with the Imperial family.