Reddit thread is interesting. Pulled this off there... wow https://www.youtube.com/watch?v=Zl12dXYcUTo
http://www.russianspaceweb.com/proton_glonass49.html
investigators simulated the improper installation of the DUS angular velocity sensors on the actual hardware. As it turned out, it would be very difficult to do but not impossible. To achieve that personnel would need to use procedures and instruments not certified either by the design documentation or the installation instructions. As a result, the plate holding the sensors sustained damage.