jryden: I'm guessing that what you mean by the current state is equivalent to the worst-case scenario, except in a few unusual cases that I've just thought of (e.g. White has borne off 10 checkers and has 5 on his ace point, while Black has 14 on his ace point and 1 on his 19-point: a backgammon is not possible, but one might say the game is in a backgammonish state).
But the game in question was not in a backgammonish state, nor was a backgammon possible, yet I was awarded 3 points. Therefore BK behaves differently than the way you and I believed it behaved.