What seems odd to me is the word choice for the literal note. 紳士魂 would be 'Gentleman's Spirit', as opposed to 騎士道 'Way of the Knight' (Chivalry). I can't think of an English word better suited than Chivalry for the situation; just thought there's no reason to point out a knightly etymology.
You're right. I made the note only at a glance, so I basically misread the word.
Also, I didn't tag the post with translated afterwards (didn't really think it was particularly significant), which normally would've made me read my own note at least once.