You see that hold all the time. Some are saying JuJu wasn't able to catch the ball. That is irrelevant. Half the time when this type of penalty is called it on the other side the field and the players aren't even involved in the play. Don't grab the jersey and you are good. The ref sees jersey stretching he/she will throw the flag.
Its just like the OL holding. If you grab a fist full on a regular basis you better be prepared to see the flags flying sooner or later. I do agree it was ticky tack and at very important part of the game.
But if the refs put the whistle's and flags away then you will get the blatant non PI calls that have changed playoff games in the past.
It's a fine line that I don't see how they can walk with the game being played at full speed.