This according to Jamie Gavin (aka PR Eagle), who informed us that the two parties were in talks before anyone else last December.
In Gavin's own words:
Pitino has just been “fired” as the Puerto Rico National Team coach before even starting. When the NCAA denied Pitino's request to have a Louisville camp in Puerto Rico, Pitino was not sure of his commitment. It was clear that Pitino’s main goal was to use Puerto Rico as a way to get the Cardinals prepared for the season. When those plans fell apart, Pitino began doubting his commitment, which led to the termination of the agreement.
It was clear Pitino's priority was Louisville, which is fine, but the PR fed felt it needed someone 100% committed.
So that ends that. At least we got a cool AnVillen ending out of the deal.