It seems that Aden has been coaching Farah more than Salazar has the last few years. Does Salazar even coach Farah any more? (I mean coaching in the sense of personally supervising workouts, etc - not the occasional email with some general advice)
Such details make a difference. It would sound much worse in the British press if the story read "Farah's coach busted on doping charges".
Of course, knowing the press, they'd be like, "Mo, how disappointed are you to find out that some of the athletes you trained with were doping, and that Coach Aden was aware of it and even facilitated it?"
And Mo would say, "well, I'm gutted, quite frankly. I can't believe that with all the trust I put in them, they let me down - especially when I was frequently Tweeting helpful aphorisms about training really hard to achieve your dreams. (I work REALLY hard, btw)".