Cook has always been a douche, everybody who has ever been his athlete for more than a year has put up with him because they got results. He's a fine coach, but a class A dick. I am sure the relationship with Edwards wasn't good from his UNC days, and it sure as hell didn't get any better when he started coaching his wife. Like was said before, Edwards just wants to manage his wife's career, while it is risky on so many levels, his intentions are what they are, nothing more nothing less.
The whole Donahue thing isn't totally surprising after the fact, as she will clearly never run under 4:00, some coaches tell their athletes that straight up, others will sugar coat it and let the athletes find that out for themselves.
The fact is, there are the Gags types who are adored by their athletes. The Salazar's who are greatly trusted by their athletes, and only coach a select few. And then Cook is an example of a guy who is great when things are great, is shit when things are shit. Unless you are truly running for yourself and don't blindly trust your one coach the way it seems so many runners do, Cook will never be your guy, but I don't think he sells that product anyway. Situations where he works with Manzano, in conjunction with Vig are the perfect set up. Leo will never get pissed at Cook b/c it isn't just him, and he can always walk away to something else.