I don't see why that means there's anything off. Just because most of us can't produce enough energy per unit time to maintain this pace doesn't mean that it's not the most efficient pace per unit distance.

Anecdotally, when I start (or re-start) running I find the pace I can run at increases quite rapidly. That makes sense with this data - although my fitness is only increasing slowly, being able to produce slightly more power actually gives a disproportionate increase in pace because the higher speed is more efficient per km.