Flagrant fouls happen on a live ball, that was a dead ball situation since Napier had already committed a common foul. Therefore it could only be a technical.
The explanation I heard, and where I was, it was hard to hear the tv so if it was explained better there, I don't know, was that it wasn't a t for the elbow but for taunting as the elbow was part of the motion of his arm after the foul.