Brian Santiago has spent the last 5 years building a relationship with KY because both Brian and TH knew that when Mark Pope moved on, and they knew that day would come, they knew KY would be the perfect guy to replace Mark Pope.
It didn't hurt that both KY and Brian Santiago are both basketball junkies that can't get enough of talking hoops, but both TH and Santiago knew that Mark Pope was not expected to be a long term guy at BYU.
Based upon what KY has done with his coaching career over the last 5 years it made it easy to target him. The real question was would they be able to land a guy that was interviewing for multiple NBA HC positions? We all know the answer to that question.