You had a reason to dislike his posts yes, fine.
But it was a personal one and you abused your mod priv's to carry out a personal attack. That is wrong and unethical.
You could have put him on ignor if you wanted or if as a mod you did not want to do that then just fly by his posts.
As I have been learning the Admin/Mod responsabilities this past yr in a smaller forum I have learned that the kind of thing you just perpetrated is crap and unethical.
If as a Admin/Mod you can't remove your personal feelings from a situation then you should have stepped back and asked a fellow Mod to deal with it in a better way or stepped back and relinquished your mod privelage's because you could not handle the situation.
Right and wrong may be something you don't care about but some of us do.
When I go over there I don't participate in most of the threads as they always turn into crap fests and it is let go. At least here we are reminded to stay on topic ( which I am not doing now because of this situation ) and although we can blast away at each other we respect each other and act accordingly.
I hope next time you can remove your personal hatred and feelings from a situation better and deal with it in a ethical and responsable manner.