lemme tell you a little story.
in 1996 I was in a car with an NBA GM. I was a fresh out of college intern. we were driving to the office from the airport. the phone rings (one of the big grey attached-to-the-car, car phones). Dallas wanted to trade J Kidd for one of two players on the roster - one an all star, one a rookie but putting up great numbers. The GM called the Owner immediately. Said "we have to do this, and do it before they change their mind". The owner (no longer an owner) said simply "No way".
Kidd went to Phoenix later. The two guys who the owner would not trade ended up having very long careers, one never made the all start team and was average. The all star made I think 3-4 games. The GM gets labeled a failure. The failed trade opportunity changed the entire course of this franchise and this GMs career.
This happens all. the. time.