Deleting a post doesn't reverse your post count if you do it yourself. I'm willing to bet the same thing is true if a mod deletes it.
It doesn't change the post count when a mod deletes it either. I realized this when I went looking for the post I roasted I8 in two winters ago. When I went to my profile, it showed I only had about 500 posts, even though my post count was near 600. It's because I had 100 posts deleted.