michrefdh wrote8-5 Art 3 d regarding touchbacks.
Art 3 ...It is a touchback when:
d. "A forward pass is intercepted in B's end zone and becomes dead there in B's possession."
Even if B committs a penalty there, its still a touchback, and the penalty would then be enforced from the 20.
michrefdh-
Perhaps this will help.
In your original study group play, yes, B intercepted the ball in B's endzone, however, the ball did not become dead there, and, because it did not become dead there, 8-5-3d is NOT the applicable rule.๐
What actually happended in your play is the offense, no longer B, (See 2-43-1 & 2-43-2) actually committed a foul in there own endzone. And since, a player on offense committed a foul for which the penalty is accepted and enfocement is from the spot of the foul, 8-5-2c IS the applicable rule, and, the result of your study group play IS a safety.๐
Again, read Rules 2-43-1 & 2-43-2 and it should help clear the air.
Oh and michrefdh, that is not just an opinion as you previously suggested,
rather, that IS the correct application of NFHS rulies! ๐
I hope this helps.