You cannot replicate the startle effect with a warned crew.
Exactly, the results in the simulator when Airbus pilots replicated the landing in the Hudson river where very different when time was allowed for the startle effect and recognition on the second attempt. On the first go they got it onto a runway, however they knew what was going to happen, when it was going to happen and exactly where the closest airport was. On the next go they crashed short after having to allow a short time for recognition and decision making.