For some reason, I just randomly thought of this. I probably got something mixed up but since Richard Alpert was back in 1970 and since, as I can remember, at least Kate and Sawyer interacted with him when they gave him Ben, then why dont they ask him what happened when they blew up the bomb? When Richard Alpert was shown the photo of them in 1970s, he said he remembered them and said that he saw all of them die. So shouldnt he have seen the aftermath of the "explosion"? Doesnt anyone care to ask him about it? Wouldn't it clear up some big question like what the hell happened? Or have I missed something?