If what Carcillo says is true - that players on other teams had heard whispers - what did the players on the 2010 Hawks know, and don't they share some blame as well?
What I'm saying is, if John Doe went to Toews, Keith, Hossa, or Sharp with this information aren't they as bad as Bowman, et.al? I'm guessing if any of those four said that this guy had to go, he'd be gone. If not more.
In short they may have some culpability if they knew and failed to do much of anything, but the psychology of the situation is incredibly complex.
One aspect that affects this is the idea of, "Person of Power." The easiest way to see that is in the "stereotypical" old scenario where a boss threatens a secretary's livelihood if the doesn't give him favors, or she tells anyone. Ditto with a teacher, coach, or anyone that is put in a position of power.
Something us laypeople don't understand (and I'm paraphrasing a lot of this from my wife, who actually works in the field of forensic psychology and is where I gleaned this information) is that in those situation, even those that you'd think could "Handle it" don't. Hence the internet tough guy attitude of, "if he ever did that to me..." when they fail to realize in the likely scenario of the alleged victim, they have every ounce of their livelihood threatened by someone who not only threatens, but assures the victim that no one will believe them. We like to think we're tough, but if you've spent some 18 years of your life training to do nothing but hockey and being needled by everyone around you that you respect to always listen and obey your coaches, and one ******* threatened everything you've worked for in exchange for sexual favors, people don't behave rationally or how they would think they would out of the moment.
This also extends to adults--or rather people over the age of majority--for those thinking, "but they were legally adults!" In the same vein as the boss/secretary example, the same rules apply--we would hold the onus on the secretary in that scenario because of the position of power held over here--and the same applies here.
The other aspect is that this scenario also applies to a lot of the players. Hell, Kane and Toews were what, 22? 23? at the time. Also, maybe they did talk to someone who was complicit in keeping the whole thing under wraps or possibly threatened themselves if they did anything. We all know almost every major sports league is an old-boys club and the NHL is no different, neither are the teams. It's not hard to think that if a player spoke up and continued to make waves (especially since the 'hawks were riding high at the time) would risk being blackballed--or outright threatened. History has plenty of examples where the bystander effect came into play where your average person did nothing while atrocities were happening around them--lest they become the target.
As you and a few other said, the letter of recommendation on this is the most damning part--and shows the 'hawks treated this like the catholic sex abuse scandals--and that shouldn't go away. People--fans or otherwise, need to start asking tough questions and start to make the brass sweat. But in the same vein, let the law actually work--innocent until proven guilty.