@rebgav: Thanks for the links. I remember getting both of those in my playthrough, but it's helpful to see them again.
She seems to imply that the tears can be more harmful to some people than they are to others, and what happened to "her" Comstock could just be some fluke, since it isn't happening to Comstocks from other dimensions.
I'm not sure I like that explanation. Seems a bit of a cop-out to me. Not that it's really a major plot point, or anything. Just think they could have done better than that.