They may have turned things around and made it into the playoffs, but it's still way too early to say that was a successful hire. It was a risky move that screamed PR splash more than anything else. Besides, they had a coaching vacancy. The Jazz did not have a coaching vacancy.
Let's say you have a company with a team managed by a guy who has been around a long time working his way up the corporate latter. When promoted to manager he hired some unknown guy to replace him. The unknown guy shows some promise and another company makes him an offer. Do you fire the guy who has been loyal to you and has worked his way up, paying his dues for years just to promote the guy who has only been around 2 years and has nothing but potential to show for himself?