It's an unspoken rule. We must vote and do the puzzle rooms, but Calhoun never said anything about needing to leave the AB rooms.

[At least he hoped that was Enjolras's thought process. Given their last talk it seemed likely, but...]

Yes... he was hallucinating for far longer than Ema or I, or at least in a far more aggressive way. [He continued staring at the AB room, frowning.] He seemed better when we left, but- but perhaps I was wrong.