Here's a fact, you can't live in the home of the Australian Institute of Sport, i.e. Canberra, and be a high profile athlete/sports person and get away with doping.
Many factors go in to making a top junior in comparison to back in the day, so hardly surprising there's always going to be one who comes along to be better to some degree.
Plenty of juniors fall by the wayside for one reason or another, just hope he can kick on with it and have a real crack as a senior.