you need to issue a /backoff on
to all your dps characters when he flies back in the air. This will reset their combat routines, clear the target list that the macro wants to engage and pause all further combat actions. Then you do /backoff off
to resume combat. They will reacquire valid combat targets based on what is available. These commands need to be broadcast to each dps character individually, so figure out how to do that via whichever communication method you're using. You do not want this going to your healers, as they will pause their healing routines as well.