I don't disagree with you, I was just using him as an example to how WE as distance runners scrutinize other athletes and tend to let observations slide in our sport.
You are stating that because he ran faster in HS than the guy whose record he broke, he should be able to run faster years down the road. This is not always the case. We see young phenoms come along every year that we think will tear up the college scene and they don't get much better or guys run great in college too and never be able to take it to the next level.
We don't know what goes on or the specific history of athletes in other countries, but yet for the most part we do not scrutinize the distance runner athletes nearly as much as sprinters. We think because a runner that is putting up stellar times when they are 16 or 17 that years down the road when they are 23 and winning the Olympics that they are clean. What if a young Kenyan used performance enhancers at ages 16 to 17 year old age? We would be none the wiser based on your logic. Heck, distance running is their ticket out, why wouldn't coaches and athletes try to find a way to cheat their way to a big pay check at a young age?
Distance runners use the "I recently started training like a Kenyan, running three times a day, 205 kilometers a week, and started eating healthy" and don't really take much heat after big improvements. They may get a casual question here or there, but no real serious heat from the public. Imagine if a biker tried to use that logic after he destroyed the field at the Tour after never placing in the top 10.