I don't think anyone will ever be confused by the "only country to use the bomb" in this context. Your pedantry is not something to not feel bad about as it does nothing constructive to the conversation
only different if you don't consider "the bomb" the way it is colloquially used. until today, i would have never considered saying "the bomb" would not have been understood as a nuclear weapon whether that was an a-bomb or an h-bomb.
