Have their been more vicious hits not called flagrant fouls, let alone flagrant 2s? Of course. Did Waiters and Redick seem to settle their differences on their own? Yup.
But Waiters elbowed Redick in the back of the head.
That invited the referees to get involved – and they did, ejecting the Heat guard. That might initially seem extreme, but I don’t have much sympathy for someone who elbows another player in the back of the head from such a stable position.