Pete,
You refer to the rule where the leeward boat is overtaking to get the overlap and hence cannot luff. Pepin was windward as far as I can tell by his description and he can then get run up.

Right or not it is a crappy move tactically unless you are match racing just that boat. As the lead boat and you screw up by letting someone up on your hip it is too late to try and run them off. Once they start taking your air dive deep, gain some separation and they will be out of it very quick. Then try and match speed with them and you still have positional rights coming into the next move or mark.

Maybe Ding is referring to the fact you had no rights as you first fouled us barging down the start line.