Sorry for the possibly confusing title, I'm not exactly sure how to word the question.
Towards the end of the movie, in the deepest level of dream when Cobb confronts Mal: How is what Ariadne did (jumped off the building i.e. died) different in effect to what Cobb did (stayed in the building, I assume he then died)?
In other words, how did Ariadne manage to 'ride' the kick by killing herself in-dream, thereby staying alive and awakening, whereas Cobb just fell into limbo by staying in the building and thus dying? Or are my assumptions wrong?