Will do :)
It happens after the part of the story where you get to talk to Yvon. After talking to some of the office workers, I reckon in one of the gameplays that I've seen, Ivan should be up and about outside of his office. Yet upon playing 2.0.0 I was not able to interact with him until the rooftop scene, and was only ever able to proceed through the story because of the debug.