Unnecessary Roughness
 

I have an enforcement question.

1st and 10 from the 50. A45 breaks away and is on the 5 when, A30 hits B10 at the 40 yard line. The covering official judges the hit unnecessary and throw his flag. A45 continues running and scores a touchdown.

What is the enforcement?
I believe that, if B accepts the penalty, the score is negated, and the 15 yard penalty is assessed from the 40 yard line resulting in 1st and 15 from the 45 and the clock starting on the snap.
Is this correct? And any references would be appreciated.
I work the National Federation Rule set, but would be interested in any other rule sets as well.
Thank you

Canadian Ruling
 

CANADIAN RULING:

The TD does not count.

Because the ball was past the LTG, we're going back 15 from Point Ball Held at the time of the ball, which was the 5, so it becomes A's ball, 1D/10 @ B-20.

As a general rule, if the foul and score are nearly simultaneous, count the score and give B the option to enforce on the try or the kickoff. Benefit of any doubt to A.

If the crew is certain that the foul occurred well before the score, then enforce it as a live-ball foul. If the runner is at the B5, that's probably clear enough.

A 1/15 @ A45, clock on the snap.

Enforce as you would any other foul. If the ball is beyond the LOS, at their own 40 when someone fouls at the 35, where do you enforce from.

Brutal? Yeah, in this case... but I guarantee that kid won't commit an unnecessary foul 40 yards behind the play again.

[nitpick]UNR, not USC. [/nitpick]

Fixed it.