It would be fine to contact him but suggest you carefully word your communication. Begin by reminding him how much you appreciated his time and the information he provided during your interview. Very briefly highlight your greatest strengths, accomplishments and reasons you are a great fit for his organization. Instead of asking if he has made a decision, how about saying how you are really looking forward to his response.
This type of communication comes off as all positive and one more reason to hire you.
With every good wish!