First off, you should've just laughed in his face. Then proceed to bash the fact that he leads quite a pathetic life to harp or even care about what others are doing.

People need to learn which business they should and should NOT get involved in.

Also, the man was probably senile.

If you've never left a flaming bag of poo on someone's doorstep. Now might be a good time. And apparantly nothing is more fun then picking on the elderly.