Here's the thing, Corus HR could have/should have stepped in much sooner. There was talk that he had been sent to anger management training. But, like in many professions, stars get a much longer leash than anyone else. But, eventually, it's long enough to hang them. Derringer felt protected from management. He was doing well in the ratings book, and his bosses must have bent over backwards to keep him happy. So his behaviour festered and he probably became worse as time went on. If they punished him for his bad behaviour, he might have changed. A suspension might have done wonders. I mean, there are only so many prime radio gigs in the city/country, and few of them could pay what Q was offering.
Saying shit about Jennifer, Jacquie, Maureen or Anne....well, it isn't their fault. You gotta stop saying Derringer made them, or they weren't talented enough. Dealing with a bully will diminish anyone, and make it harder for them to shine....which might be why he acted like he did. Didn't want it to be Derringer & Halloway in the Morning! It's always been and always will be Derringer in the Morning!!!!!
I enjoyed listening to him once in a while. But I can totally see him being a massive asshole. It wouldn't be something you would see/hear on the air, he saved that venom for before/after the show and during commercial breaks. It was likely important to him to be seen as a fun friendly dude on the radio.
The final point here is that HR is useless like tits on a nun or the 'g' in lasagna. As we should all know, HR is to protect the company, not the workers. But, when there are serious allegations of harassment or bullying, they need to do something. It doesn't matter if it's the CEO. Not doing something opens them up to lawsuits with punitive damage.