What is not being acknowledged - particularly by the Salazar defenders, who rely on a selective and favourable reading of the report - is that USADA would have confined its case to what it could prove on the limited evidence it had. Had it taken a broader and more speculative approach it would have seen its arguments shredded by NOP lawyers. It couldn't afford to do that. The case against Salazar then is what the USADA believed would stick; and not what it might suspect would be the full story about Salazar and NOP.
We are not so confined. Stepping away from the legalisms of this matter - which were still sufficient for the USADA to declare that Salazar had "orchestrated and facilitated prohibited doping practices", and ban him for 4 years - we have a controversial coach who has been the subject of speculation for years, who we know ventured into using substances when he was a competitor, who has drawn a pool of athletes to his programme based on his reputation for getting results, and many of those athletes (like Farah) have shown dramatic spikes in performance since joining him. What did Alberto have to so aid his charges that other coaches didn't have? The USADA findings suggest a methodology that had less to do with superior training than finding an edge through developing ped's, some of which were legal and some that were not. How can we believe that his athletes didn't benefit from this method - whether they were aware of what he was doing for them, or not? As has been pointed out earlier, their not knowing would not amount to an excuse if they too were breaching the rules.
USADA has not gone after the athletes because it is highly likely it wouldn't have had the evidence to prove a case against individuals, and it couldn't make a general case against NOP athletes without impugning all. But when a leading coach is involved with illicit doping practices the obvious intended beneficiaries are his athletes. The IOC is right to ask WADA to investigate.