Criminal Law Questions? Ask a Criminal Lawyer.
I suggest you can have him put his request in writing and mail it to the District Attorney.
Also, you can call them and see if the prosecutor will speak with you. They are under no obligation to unless you file an appearance as pro se. Of course, you want to be careful what you say to the DA as anything your say can be used against you.
And you also might want to tell your attorney or Public Defender the situation and that he does not want to go forward.
IF you have not been served with charging documents then you can consider consulting with a local attorney. That way when you are served, you will be ready.
And it is possible an attorney may be able to have the matter dismissed given there were no witnesses to the allegation that you hit him. Remember, the case must be proved beyond a reasonable doubt