Overtaking boat had no rights until overlap was established. Initially, the leeward boat must give the windward boat room and opportunity to avoid, but that only holds for a brief period (RRS 15). Leeward still has the over-riding responsibility to avoid contact when it becomes evident that windward is not keeping clear (RRS 14b). Leeward should have hailed "protest" and continued on her merry way - contact is slow.

Proper course is in there, too (RRS 17.1). Leeward has to sail proper course as though windward weren't there when becoming overlapped within two boatlengths to leeward - following puffs is fine, but a trip to the moon is not warranted.

Ties back into the other thread on advice - overtaking boat should have recognized the issue developing and made a better pass while in the puff. In really light air like that, I would have gone higher with the puff, gotten some separation before the pass, and taken the other boat on my leeward side. He'll get the puff you're on eventually, but you'll conserve apparent and momentum by staying away from him.

I love that light air stuff!