[While Ren sits down when Riza indicates it, he largely seems to be doing it out of politeness and less out of actual concern for his own condition. Nonetheless, Riza's reaction to Roy's name and the change in her expression are answer enough to his question, even if she doesn't quite agree with "friends".

At the question of whether he knows anything, Ren looks up towards the roof, considering.] I didn't see anything...definite, if you were hoping for closure, but I can tell you he didn't just "not come back up" with us. We lost him when members of our group were getting picked off. The first time I met him, he was following a hallucination, and that was early on. I don't think he would've had as much luck against the monster's mind games alone.

[He doesn't specify that he's pretty sure it was a hallucination of Riza that he was trying to follow, because he knows way too many people who'd start blaming themselves with that kind of detail. But even in his admission that he doesn't know anything definite, he sounds sure in what he does say, if somewhat careful in how he's phrasing it.]