Can a NCO that start Terminal Leave in a Month be flagged. And his terminal leave be revoked?

I have a Junior Team Leader (E5) that once he began to have less then 6 months left, started to show lack of discipline and bearing, and finally blatantly disrespected his Squad Leader. His terminal leave has been approved and starts on the 11th of June. Never delt with this type of insubordination before any advise.