If you're working on a group project and you're accused of cheating or some other academic misconduct, you have to bear in mind, it's not necessarily that you're looking to throw your fellow students under the bus, but you have to look out for number one. It's not necessarily a team effort in the sense of responding to academic misconduct allegations. Certainly, if a unified front is going to be most appropriate to the circumstances that can be kept in mind, but you have to look out for yourself.
You have to understand that when responding to the allegations, you should not engage with the school in any capacity until you've taken the necessary precautions. You cannot depend on the school, the professor, the conduct office to naturally be doing the right thing, or understanding the allegations or even the dynamics of law that led to the allegations.
Having an experienced academic misconduct attorney advisor's going to be your best ally in helping to understand and navigate the process and would be able to let you know what's going to be most appropriate in terms of responding to an allegation that involves other students. They should be involved as early as possible in the case.