NF: 10-2-1, "It is a double foul if both teams commit fouls, other than unsportsmanlike or nonplayer, during the same live-ball period ( and then goes on to explain several issue that don'y apply to this situation)".
A's foul for Illegal formation is simultaneous with the snap, and B's unnecessary hit is a Personal foul, both live ball fouls. Penalties offset, replay the down.
|