There are few people in the NBA who dislike each other more than Boston Celtics president Danny Ainge and Miami Heat president Pat Riley -- and it has been this way going on four decades.
They hated each other in the 1980s, when Ainge was a guard for the Celtics in the Finals against Riley's Los Angeles Lakers.
They hated each other in the 1990s, when Ainge was playing for the Phoenix Suns and Riley was coaching the New York Knicks and they both were involved in a brawl. Ainge and Riley ended up on the deck, Riley ripping his pants. It led to a record 21 players getting fined or suspended.
https://www.espn.com/nba/story/_/id/29847095/nba-playoffs-why-next-chapter-heat-celtics-let-us-down
35 second mark and 2:40 in slow motion - Pat Riley (coach in a suit) tackles KJ, knocking to floor (after Greg Anthony sucker punched KJ, coming off the bench, when KJ was being held back by teammates) -
2 minute mark - Slow motion original play that instigated whole thing