I think the discussion has gone beyond the intent of rule 17. 17 says that: If a boat clear astern becomes overlapped to leeward within two of her hull lengths to leeward of a boat on the same tack, shall not sail above her proper course while they remain on the same tack and overlapped within that distance, unless she promptly sails astern of the other boat. Here the proper course for the lee boat is to stand clear of the windward boat.  When the overlap was established to leeward of the clear ahead boat, the lee boat gave up her rights as leeward boat and her proper course to the mark is not relevant. Rule 17 allows for this in providing the leeward boat to sail astern the other boat to reassert another course.    

Paul, I don’t disagree with anything you just posted, though I’d add one item. 

Differentiating between the information that an RC might submit to indicate their intention to protest a boat, and the actually filing, can be a distinction without a difference. 

The only requirement of a protest filing at the time of filing is a description of the incident. Here, the RC is also identifying Protestee and Protestor (which is not actually required at the time of filing .. so that’s “extra”). 

If the RC wrote on a piece of paper or emailed/delivered to the Race Office within PTL …

 “Race Committee is protesting Boat 123 in race 1. She missed the offset mark at 1st windward rounding”

… that’s a valid protest filing. 

The communication to those in charge of the ONB of the importance of that being posted on the NB before the PTL would also be the same either way. 

So … absolutely you could separate those 2 operations … have someone in the RC post the notice of intent to protest and then file something later, but practically they are typically combined … and as others pointed-out “automatically” done simultaneously when using RRoS. 

The issue with posts on the Italian channel being sent despite the preference being unchecked has been fixed.  That shouldn't happen again.

Il pannello per l'impostazione delle preferenze non funziona.

Well, thank you all.
Thanks to Mark, reminding me of the case book. Case 24, is very clear about "responding prontly". 
So that's it; so for the PC, in a hearing, should determine wether the prompt action taken by the boat that acts to keep clear, was, or was not, made in a seamanlike way. Tough.