playBunny: I agree with everything you said, except that awarding a backgammon when it is still possible seems conceptually clean to me (if not ideal, nor necessarily fair). In chess, if your opponent loses on time and you have one single pawn against an army, you still win the game (if you don't have the pawn, it's a draw).
But the way it is seems acceptable to me, and I certainly wouldn't make a bug record or feature request of it, since there are more important pending ones about backgammon.