How can this be? Is it because he's the OP? I've certainly never noticed that I can review suggested edits to my own posts. (And if I can, then I would like to know how/where to do so.) Or is something being displayed incorrectly?
Yes, because he's the OP. You can review suggested edits to your own posts when you are quick enough to get to it before others approve or reject it. According to this you get an inbox notification of suggested edits on your own post. The OP's vote is binding, so the OP can single-handedly approve or reject a suggestion.