Did WADA intentionally sabotage Russian doping probe?

On the eve of the Summer Olympics in Rio, Russia claims 270 of its athletes have been cleared for competition. For the man who helped expose Russia's state-sponsored doping, that's a source of frustration. Jack Robertson, former investigator for the World Anti-Doping Agency, says WADA repeatedly thwarted his efforts to clean up the Games. He was interviewed extensively by David Epstein of the investigative news group ProPublica.