While it is relevant to Harry's desire not to have to kill, it was not as related as the other quotes were to his struggle between idealism and realism in fighting a war.

I think it's safe to assume it's deliberate, although I do not think it is the same instance.

Guess I just haven't read enough.

You are certainly not the only one who was reminded (eerily so) of a part of Fate/stay night that I won't discuss here for fear of spoiling the visual novel for anyone who hasn't yet played it. Quirrell's talk with Hermione made me think of a certain character from FSN immediately as I was reading.