When I first got to Novac on Benny's trail, one of the first people I spoke with was Manny up in Dinky because it was daytime and he was on his shift. He doesn't want to give info on Benny until the Ghoul problem is taken care of but he does talk about Boone and mentions Carla, even calling her a b*tch because he didn't like her. I think he was jealous and thought he was going to lose his friend to her. Good friends, really good friends aren't like that and they don't gossip about a friend's personal life to other people. At least that's how I feel. I tend to think that Manny was obvious about not liking Carla because Boone says, "I could tell he was glad." If he could tell, Manny didn't hide it well enough and yes, Manny may not have offered to help him find her (or other things we could write in.
). We learn that Boone says Carla is dead but no one knows how he knows that - and he's not talking at that point. Again, I think I'm remembering in the right order.
And yes, death can change many relationships...it's like a tide with an ebb and flow depending on people's connections with each other. I love how this game has drama and life lessons in it. More of that, developers. It was compelling.