Great description, Jeff.
On the positive side, this incident shows what barging actually looks like. More often than not, boats with no hope of "closing the door" will claim that others are barging.
Again, while there is no definition of the term, if there is enough space for you to sail between the RC and the closest leeward competitor, you have not barged.
Also, if the leeward boat shuts the door on you, and you avoided her and the RC boat, I would say that you didn't barge. You went for what you thought was an opening, and you were proven wrong. As long as you don't try to force your way in anyway, you haven't done anything illegal.
So, to me anyway, barging is only when you come in with no rights, and force other boats to avoid you so you can get by the RC boat and start where there was no room. Anything else may be an "attempted barge."

Mike