It's a pretty difficult one to get since it's connected to Julian's day 2 anatomy lesson evening scene as well.
It's easily the most tricky one, since it needs the anatomy scene as a prerequesite. Julian should ask you about him, then he'll talk to you again in the opening scene of day 12 with a choice about him, and then if you decide to leave the scene should trigger with the correct selections.
Don't remember the exact wording of the options needed right now, but maybe that'll put you on the right path.