Usually they do give each other the information out of courtesy.
They way I understand it, and I may be wrong, is that one of the reasons Nel charged Oscar with premeditated murder, or rather murder under sections 6 and 51, is that under section 6 you do not get bail unless there are exceptional circumstances (medical reasons) or if you give a statement explaining what happened.
Oscar refused to talk to the police before the bail hearing. But in order to be considered for bail under a section 6 murder charge, he decided to give a statement. And now he's bound to that statement and he can't change his story too much. Clever of Nel.