Russia doesnt have any real rule of law and there is lots of corruption throughout the government including the court system.
If you have money stolen from you that ended up in Russia, I would consider it lost. The law firm in question may be taking such a hefty fee because they need to pay kickbacks to government officials.
In any case, the amounts being asked for far exceed normal contingency fees charged by western lawyers.
in their released QA, i'll link in a bit they say they would not be bribing anyone and make "guarantees" everything is above the board --- rolls eyes