Looking past the issue of whether the kid is being over-trained for his age, I think people are overlooking the obvious when it comes to the so-called WR for the road 5K: My guess is the kid cut the course.
Seriously, it was a freaking Turkey Trot. The race organizers were probably short on course marshals, thus creating opportunity - intentional or not - for the kid to slash time by turning a block or two sooner than he should have.
Happens every year in my town's annual Halloween 5K. A bunch of 11-year-olds jog the course in their cumbersome costumes and still cross the line in sub-19 because there is no one on the course monitoring runners and the punks' parents never got around to teaching them the honor system.
So this Zach Blum ran 18:30? Doubtful...