As I understand it, the rule is that on an inadvertant whistle, the offense has the choice of replaying the down or taking the results of the down? I end that with a question mark because it's unclear. I've seen plenty of times over the past 20 years where the whistle simply ended the play and it was what it was. If that meant the offense lost yardage, so be it. If that meant the defense recovered the ball but was not allowed to advance it, so be it. Just looking for clarification on the actual rule and if it has been changed recently.