Before the speculation gets out of hand, y'all ought to read the (unusually good) profile on Castille from Runners World from 2016:https://rw.runnersworld.com/selects/masters.html
He ran 28:49 for 10k at Stanford in 2003 or 2004 after 3-4 years of real training. Had he started when he was in high school or even college and developed like most elites, I imagine he'd be capable of 61-62 for the half. It's not crazy for a talent like that to run 2-3 minutes off their lifetime best in their mid-40s.
I read this article when it came out, and have been fascinated with Castille ever since. I am in my late forties, and picked up running late in
life, and so I found his story very inspiring. I love a good "bad to good" success story, as they teach us what we are truly capable of, what truly lies
His race times are otherworldly, and I can see why people have doubts about whether he is clean. I do not know him, but, without evidence, I would never think he is anything but clean.
I will probably never meet him, but would love to see him someday, perhaps at a race, and talk about life, running, redemption.
All the best to you, Kevin. We old guys know how HARD it is to do what you do. Peace and God bless.