I'm not defending agile, but what is described in the abstract cannot fit with what I am familiar with as "agile" - an almost defining quality of an agile process (as I was introduced to it) is that at any given moment, the status of the project is transparent and well known by all stakeholders. Thus, if you discover all of a sudden that the project is late and over budget, you have been sleeping at the wheel.

(Note: This is not a "no true scottsman" argument. And I honestly think agile is only a good match for some projects, and not e.g. infrastructure. Nevertheless, this does not sound like the "agile" I know).