THe zombies being stationary with colourless eyes ties into the timeline. On nuketown zombies, at round 20 or so, the zombies eyes change to blue. So at round 20 or so, Richtofen takes control. That is what is most likely happening at Tranzit, we are starting the game at the moment Richtofen gains power. Marlton's quotes from the fallout shelter stop before Richtofen takes over, so it would make sense that he was in the fallout shelter for the nuke, then made his way through the tunnels to the bus depot. (There is a passageway leading undergound that says "Shelter" right out the bus depot.)