If Alice died, and Bob wishes he had died instead, that would be Survivor Guilt. This is when Bob wishes Carol had died instead. Then, those with Survivor Guilt may think that others think this. Sometimes used to Lampshade that the target of the comment is The Unfavorite. A variation might be "I should have aborted you," or "You were an accident." An easy Kick the Dog (or Moral Event Horizon) line. On the other hand, if you, Dirty Coward that you are, survived by sacrificing the other character, expect no mercy. Compare I Wished You Were Dead. Saying this can occur during a Moment of Weakness.