Yes, you are SOL, it is good that you mentioned common courtesy, but maybe he didn't know what the words meant
If he really is a "green" hunter it may be nice to have a short civilized conversation to explain to him why people should or shouldn't do those types of things. You never know if he just hasn't been taught hunters ethics and doesn't have a mentor. Use your own discretion.
I don't know if MI has laws about using radios while hunting, but I am sure it depends on if he was using it to assist in taking game, or just staying in contact with a fellow hunter. If it happens again, and you hear him using it to an unfair advantage, then you could report him.