The way this play is described IMO would best be treated as a DB-PF. Since the "block" occurs at about the same time as the tackle, and 20 yards behind the tackle, I would offer that the intent of the rules would be best served by calling it DB in that the block did not result in an "unfair advantage" for the actual ball carrier.

Also, as described (at least under NCAA rules) this is definitely a foul. This type of play has been cited by the NCAA rules committee for the last several years, and is again included as bullet 9 under the Protection of Defenseless Players section within the Point of Emphasis.

When in the judgement of the covering official the player is "out of the play" and therefore has no reasonable expectation of getting hit, we should have a flag when he does get hit. I would also agree with the preventive officiating idea if I was the trailing official and offer the standard "let's not do anything stupid" if we see anything "developing" well behind the play.

You're correct. You're not an NFHS expert. If you were, you'd be familiar with the POE's over the last few years. You'd be familiar with what HS officials are told at state and local clinics. This play is illegal and the Fed and the States want it called.

Stick with NCAA.

Just to comment on the "play to the whistle" point that was brought up. I made the mistake saying most officials. This was a generalization that I've made from my experiences outside my own crew. I've worked with crews that have acutally said "play until the whistle", but in my normal crew's captain's meeting we tell them to "watch for the play being dead i.e. player obviously down by contact or OOB and incomplete passes, but if you are unsure to be aware of ongoing play until the whistle." Regardless of what we say though, alot of coaches coach play to the whistle which I agree can be stupid and dangerous.

Will do, BASKETBALL ref. I'll stop trying to clarify my understanding of your rules. Wouldn't want to know more or understand anything better, now, would I?

Now, on a more civil note ... can you post for me the POE's you're talking about - I have read the ones that get posted here, and don't recall this one ... but maybe it just hasn't been posted before. Assuming said POE exists, I'm wondering what the reasoning is behind making assumptions that certain players on the field who are a certain undefined distance from the play would never end up having an effect on the play, and thus are unblockable.