I am just catching up with this thread but as for why some events can be different? Think of it as being a bit like Doctor Who. *little* things can change, but there are certain events within that flow that are *fixed points*, things that if they change blow the entire timeline to Hell. *Those*...
This look on Reno's face *killed* me. He looks like his whole world just died. He and Rude have always been my favorite characters in the game and they did the boys so well.