If you fail any group exercise, they will ask you to resit that. I went in may 08 but didn't go to phase4. However, they also called me back stating that i was very close to their standards. My feedback said that I failed one of the group exercise as they found me dominating the group (which I admit because no one was speaking or discussing and I, only then, had to jump in to define the objectives of our task... wish I had stayed quiet).
However, due to this fact they have asked me to repeat from phase 1 and I thought for what reasons .. despite passing it. But never mind, never afraid of it. I am back in Nov 08 and if i pass I will not need HSBC to fund me .. I worked like a donkey
.. (still a donkey
) and sacrificed much.
I am also a graduate and an IT engineer/consultant so will always have a backup plan and side work. so the bottom line is they may ask you to sit any exercise.