An instructor and student can do whatever they want in a suitable aircraft as long as the student is willing to pay.
If the FI's licence specifically states 'No aerobatics' and the FI then instructs aeros and is paid for doing so, he would be in breach of the law. BillieBlob will argue about this until the cows come home, but it's the way it is.
It is perhaps for such a reason that EASA has chosen to tighten up on
ad hoc aerobatic instruction conducted by those who have never been formally required to demonstrate their competence in the discipline. So those who are properly qualified are shortly to be inconvenienced thanks to industry cowboys....
Anyway, this thread is about military accreditation, not about how some people think that they have discovered loopholes.....