There were pretty strong indicators that Chiarelli wasn't a good option for the oil ahead of the hire; this is the guy that traded Seguin and Kessel at 21 years old. He got lucky that Toronto regressed making the return far better than expected when he moved Kessel, but the guy had a track record of trading elite cost controlled assets. What does he do, a year in trades a 23 year old Hall for Larsson.
It's not even like people didn't point this out at the time either. Chiarelli was a step up from McTavich and the mess that preceded him, but the reality is, it was a mistake. Nicholson admits it, and even identified a big part of the problem in a recent interview; they only interviewed one guy, they never conducted an in depth search for the right GM, they just hired the first available guy with a name.
So no, the Oil didn't do it right, and hire the right people or do things the right way only to have it not work out. They made mistakes that lead them to where they are now, and they can even admit their mistakes, and even though it's easy to throw Chiarelli under the bus after you fired him at least Nicholson is owning that he's the one who made the mistake in how he went about hiring the guys they had in the first place.