Untimed Down?

[Snake~eyes]

Originally posted by Patsfan2431
:04 seconds left in the half. A has the ball 3rd and 10 from B's 45. A12 throws a jump ball in B's end zone. B picks the ball off as the clock hits 0:00. B runs the ball all the way back for a TD. During the run back, B55 is flaged for a block in the back at B's 45. (B still constitutes the defensive team on the original play). What are the options? What if B was stopped short of the goal line (No TD on the play)?

Team A can accept and enforce the penalty for an untimed down or they can decline. If they decline we have a TD(in the case where theres no TD, the quarter would be over).