In July of 2015, a bizarre story about DeAndre Jordan breaking an agreement to sign with the Dallas Mavericks was dominating the NBA news cycle.
It was reported that Jordan had verbally agreed to a 4-year contract with the Dallas Mavericks worth $80 million during the moratorium on NBA free agents — the period where teams can negotiate with players but not officially sign them. The news was broken by Marc Stein and confirmed throughout the media landscape.
These types of agreements are standard operating procedure and are generally considered to be set in stone, even before pen is put to paper.