
If there are a line of zeros (0:00) up on the game clock when the QB has exited the playing field, then by rule, the game is officially over and therein, the jurisdiction of the officials, in as far as the game itself is concerned, is over. Throwing the flag with one's back to the clock is naturally reactive, but once the officials go off into a quieter corner of the football field and rule accordingly, the flag is summarily picked up, no penalty within the game itself is to be assessed as the game is now effectively over and there is a winner declared.
That being said, at that juncture, the officials are now deemed as "witnesses" to those actions for any administrative or a state criminal or civil matter is concerned. If the R "was bumped" or "did bump" the coach, now falls into an administrative and/or legal situation.
I think that the officials acted naturally, but fastly came to the realization that the game was effectively over and was now out of their hands.
To wit, it's now up to the governing body of Tennessee high school athletics to administratively proceed; and quite possibly to the appropriate legal jurisdiction, albeit the county or state, to proceed further in their appropriate legal venues!
