Was the QB out of the tackle box?
I was at a game where the back judge threw the flag for intentional gounding. Really. He missed the spot of the foul by about 20 yards.
There was no doubt about the intent as the ball hit about lane 8 of the track surrounding the field.
When I was talking to the opposite wing official later, he said the coach (whose QB threw the ball) didn't have a problem with the call. It was that obvious. Except to maybe the R.