Previewing a new Forum topic causes it to be published? Answered

Earlier this morning, I was editing a new Forum topic ("Ionizing vs. non-ionizing radiation, units, and safety" in Physics). I hit the [Preview] button to check whether I had messed anything up. I had (missed out one of the ending quotes for a boldface bit), so I clicked on "step 1: Edit" to go back and fix it. I went through the Preview -> Publish steps again. and thought I was done.

Much to my surprise, there were two copies of my topic posted! The first was the version I had previewed (above), with the mistake. The second was my final version where I actually hit the [Publish] button. I've deleted the first, of course, to avoid confusion.

Should the Preview action actually generate a published entity?