A cute story about roshei yeshivos and smoking: In my younger days the boys voted there should be no smoking in the beis medrish. The next day we say one of the rabbeim standing in the doorway and smoking. A few of us told him, respectfully, that we voted no smoking in the beis midrash.
Ever mindful of our chinuch, our teacher said “When this place looks more like beis medrish I’ll stop smoking.” We accepted his mussar and needless to say he lived up to his end of the deal.