Today, in the suggested edits review stats,
How is this possible?
He reviewed a suggested edit on his own post. Note that his name is highlighted in blue on the reviewers roll call:
If you look over his review history you'll see that this was his 21st suggested edit review today.
The OP is always given a veto vote on suggested edits on his own posts, regardless of review queue limits.
reviews on your own edits don't count as reviews
but can be added to review count.