Saito was written to be too stupid here (it could have been he was too worried for his loved one, Louise, and lost his mind, but it didn't give me that kind of impression. After all, he was chasing all the women all the time, so he's not that much in love with Louise, just somewhat). In Japan that Noblesse oblige was probably stronger than anywhere with the samurai who were a social class of their own above the mundane people but who were always willing to lay down their life for their daimyo and their honour without a moment's hesitation (idealistically anyway but oft in practice as well). Makes Saito a pretty poor Japanese not to know even that...