There is also the possibility that both sides realized that things were not working out to either sides satisfaction. Maybe what we need is not something you're able to do well and what you can do well, isn't really effective enough for our needs. Maybe your strengths in our areas of need, aren't enough to overcome your weaknesses in other areas of need. In IW's case, I feel like his defensive troubles and lack of consistency were problems that were not getting better. Since a lot of coaches base playing time on what they're seeing in practice every day, I would guess that Pitino was looking for 2-3 weeks of consistency and solid defensive performance in practice and wasn't seeing it, hence, not a lot of floor time (unless he spotted occasional match-ups or game pacing situations) for IW. For a lot of coaches, consistency is VERY important (I've had several coaches tell me, "I need to know what to expect from a player when I put them in a game. If I'm not sure, I'm hesitant to play them".) and practice is where you show that coach if you're earned playing time. It appeared to me that Pitino could never be sure of what IW would do on the floor.
Instead of trying to force a square into a round hole, it looks like they agreed to help each other get you into a situation where it's a better fit for both parties. I think both sides handled the situation with class. I watched 80% of the games this year, and I saw a guy who was disappointed in the situation, but was very supportive of his teammates and tried his best when he was given the chance.
Sometimes, talented individuals aren't a good fit with the overall needs of the team. Happens all the time in life, sports and business. Sometimes a new start is a good thing for everybody.