this is my argument with people who say bolt could have been faster with better training or more dedication, or that randy moss would have been a better WR if he'd smoked less weed, or whatever. everyone is different, and when someone is the best ever at what they do -- or even very elite -- it's hard to believe that doing things differently would have improved their results. usain bolt is the fastest 100m runner of all time by more than a tenth of a second! randy moss was completely uncoverable for years!
if this dude can make four olympic teams with 70 miles a week, and when he tried to run more got hurt, then who's to say that if he'd had more driven coaching he wouldn't have broken down in his early 20s and never competed at an international level? counterfactuals are all problematic; counterfactuals second-guessing success more so than most.