The officials made the correct call. There was a foul on the defender and a whistle; thereafter Grayson led with the elbow above the shoulder in an attempt to clear out. That's not allowed. Had it happened prior to the whistle it would have been a flagrant 1. Since the play was dead it was appropriately called a dead ball technical foul.
There was some acting on both sides. The Carolina player was holding his nose but Grayson's elbow was nowhere near it.
Not a good look, but not a felony, either. Not even close to the take-down of one of the Georgia players by a Kentucky player last week. Kentucky guy grabbed the Georgia player by the upper arm and body slammed him like a wrestling match. For some reason I don't see ESPN going crazy over that play, clearly dirtier than anything Allen has done since the Elon game, and I don't see PA-PLAYA calling for suspension of the Kentucky player. Curious.