B1 intercepts A1 pass in the end zone where he is grabbed by the face mask and fumbles the ball out of bounds at B's 3 yard line. Where would the penalty be enforce from ?

Deja vue all over again...
 

This is a 2001 NF rules interpretation that has been debated ad nauseum on this and other web sites.

Don't have my 2002 case book with me but the NF has updated this play to give the correct ruling (Hey BBR you were correct; just wanted to acknowledge you because I was wrong on this one earlier):

The basic spot is B's 20 yard line because B1's run ended in B's end zone.

Please help me out; I just want to make sure I remember the case book play correctly (its under rule 10):

B can decline the penalty and take the results of the play. B's ball 1st and 10 at B's 3 yard line.

B can accept the penalty and have it enforced from the basic spot. According to the NF case play the basic spot is B's 20 yard line. After administering A's foul it will be B's ball 1st and 10 from either B's 25 (5 yard face mask penalty) or B's 35 (15 yarder).