When Renko first travels into the past and is seen carrying Demichev through the burning facility, a future Renko appears and shouts, "Renko, stop! Don't let Demichev-" before being killed by falling debris. Near the end of the game, when Renko has a flashback to saving Demichev's life, the Renko that was killed by the falling debris was able to shout the entire warning of, "Renko, stop! Don't let Demichev live!"
The backwards "R" is actually pronounced as "ya." In the Cyrillic alphabet, the letter R is represented by the letter P.