I guess they are more likely to give offers to people who have AAA predictions, rather than AAB. It simply depends on supply and demand I think, if they have enough AAA applicants to fill their quota then it is more than likely that most offers will be given to AAA people. But if they do not have enough AAA applicants, I would assume they would then consider AAB people.
It's nice to know that they are hoping to keep offers at AAB - even Sheffield has gone up to AAA this year!
Zip It123, has your friend got an offer for straight Law, or a combination with a language or something?