The 29-year-old opted out of his contract with the Heat following their loss in the NBA Finals to the San Antonio Spurs after spending four seasons with the club.
After a protracted saga, James signed with his hometown club the Cavaliers in a reported two-year deal.
"He seemed at peace with the decision," Spoelstra told reporters. "We don't have any regrets. He shouldn't have any regrets. It was a historic four-year run."
James won the NBA Championship twice in his four years with the Heat.