There is something dirty and dangerous about leading with the crown of your helmet. If you get clotheslined or speared the other team will be penalized. There's no rule about spearing unless you lead with your helmet, is there? Also, if it's dirty to drop your pads when contact is about to be made, then pretty much every ballcarrier in NFL history has been dirty pretty consistently. You are pointlessly talking about dropping your pads when this is not at all what is being described. It will come into the conversation, though. Players drop their pads when contact is coming, instinctually. When that happens, logically, the heads drops with the shoulders and opens up the almost certainty that refs are going to make mistakes (especially when the league office emphasizes this) and penalize runners when they don't lead with the crown of their helmet. I this really is as insignificant an issue as the NFL claims, then the best case scenario is that it's needless regulation that gives refs, who already have a tough job, an extra opportunity to make mistakes and bog games down.