On the submarine, Bierko's assistant reads out the passcode as alpha-255-tango-Romeo-99, but Bierko enters (as seen on the screen in Cyrillic characters) ih-255-L(ima)-Romeo-99. (The 'ih' is an approximation of the actual Russian character.)
A major plot point is a critical recording on a portable drive being erased. Chloe O'Brien, of all people, would have made a copy (probably several copies) of the recording before she did anything.