All planes need a certain glide slope to land. If a plane would be below that slope after the turn then the pilot would not have made the decision to turn back. The decision making performance of the pilot is part of the exercise.
If, given the aircraft and the day, the plane would pass below the necessary flight path then another decision would have been made.
Stalling the plane is never an option.
As I have said this is standard training and this particular exercise is common.