re: Saints 28 @ Jets 13 | FINAL | Preseason Game #3 | NEXT: vs. MIA - Thurs. 8/29 - 7:00 PM

other penalties don't usually rely on multiple refs looking at different things

you will see conferences for defensive holding if the QB might have been out of the pocket or for pass interference if the ball might have been tipped...but usually one ref can make a call.

For intentional grounding, the qb needs a clean release, the ball can't be tipped, he can't be out of the pocket and if he is the ball needs to cross the LOS, and there can't be a receiver in the area where the ball landed. It is really hard for one ref to watch for all that and still maintain their other responsibilities