ESPN.com's Tim Bontemps shared the league's official release regarding the matter:
The Cavs signed McCaw to a two-year, $6 million offer sheet in late December. Because he was a restricted free agent, his previous team, the Golden State Warriors, had the opportunity to match that offer and re-sign him.
The Warriors declined to exercise that option, paving the way for his move to Cleveland.
McCaw appeared in three games for the Cavs before the team released him on Jan. 6 to make way for Cameron Payne. Some wondered whether the Cavaliers essentially acted as an intermediary to get McCaw out of Golden State and allow him to become an unrestricted free agent.
While McCaw's salary hit on its own wasn't significant, the Warriors would've had to pay $11 million in luxury taxes if they had matched Cleveland's offer sheet.
The New York Times' Marc Stein reported the Warriors had requested an investigation by the NBA to determine whether Cleveland was guilty of "salary cap circumvention." Stein added that the Cavaliers could've been fined between $3 million and $6 million or lost draft picks if the league found the franchise had failed to properly follow CBA rules.
Forfeiting a 2019 draft pick would've been a massive hit for Cleveland, which owns the NBA's worst record (9-35).