The pin is an obstacle surrounded by navigable water. If you aren't making it after the gun and you luff up to shoot it, you'd best be sure that no one to windward of you is forced to change course to avoid you or you will be in the wrong.
Not so, according to the rules interpretation provided by the answer to quiz one at
Halsey Quiz.
B's proper course in this particular case would include the right to luff in order to clear the Race Committee boat(pin end boat) and start the race. (See definition of "Proper Course")
