It seems as if ING is an area that has a wide range of philosophy of when to call, and when not to call. I have seen similar plays to both above that have been called, and not been called. How do we know without further AR's to guide us? It would help if there were more memos as mentioned, giving examples like "--running back is blocking in the pocket. protection breaks down. running back slips out of the pocket (still behind NZ) and TURNS BACK TO FACE HIS QB. qb, while still in the tackle box, throws the ball and it lands 3 yards shy of the running back = NO FOUL --running back is blocking in the pocket. protection breaks down. running back slips out of the pocket (still behind NZ) and either continues to block or begins running a pass route WITH HIS BACK TO THE QB. qb, while still in the tackle box, throws the ball and it lands 3 yards shy of the running back = FOUL FOR INTENTIONAL GROUNDING.
Even with such play scenarios, there are going to be areas of gray, more than with other rules in which we will not know for sure.