I think it's part of the second-chance pool. If you look at the submission from OP, it was actually submitted 20 hours ago.
It is indeed coming up from the second chance pool.
I wasn’t being critical of the project (actually quite the opposite), more surprised at the situation. According to what it shows, one was posted 12hrs ago, the other was 10hrs ago, so why wasn’t the second submission two hours later by a different user handled appropriately? You’d think that they’d at least have logic to prevent the exact same url from showing up on two different submissions at the same time.