2025 Case Book, play 6.2. (paraphrased):
R returns K’s scrimmage kick for a TD and (a) during the kick, K commits a holding foul, or (b) during the runback, K commits a BBW foul.
In (a), the TD counts, and R may take the penalty ONLY on the try.
In (b), the TD counts, and R may take the penalty either on the try or the KO.
What’s the rationale behind this difference?