I was talking with another guy about this play. I think in slow motion, it looks like a flagrant foul, also considering the damage to Miller's mouth.
However, in realtime, I questioned whether it was a foul at all. It wasn't like Miller went flying, or that he got clubbed in the head. Rondo smacked his face from behind. Now, I'm no expert, but how does rondo cause so much damage coming from behind with only his hand touching Millers face? I mean a bleeding mouth and messed up teeth come from elbows and punches, not from smacks to the face.
Then I saw a replay. Indeed, Rondo does swipe at the face, but the real damage comes at the end. It looks like Miller falls into the elbow of Pierce, right in the mouth. All of a sudden, he's got a bleeding mouth and claims it's from Rondo's hit. In actually, he flopped right into Pierce's elbow.
Maybe I'm wrong, but that's what I think happened.