We shall see very shortly, but my guess is the same as yours.
Prior can legitimately claim they have been defending testimony against the wording of the indictment, and now the state - having already rested its case - wants to change that charge to something else. That's not fair to the defendant and his rights, and I see no way the state gets to say "Never mind, let's have a do over."
This would lead to a dismissal with prejudice of count 4 (JJ murder) but does not impact the other charges.
It's a big deal that the state has already rested its case.