[[Chosen (Buffy episode)]] says "The core four
share a moment talking
about going to the mall after saving the world which causes Giles to
say "the earth is definitely doomed," echoing the end of the second
episode of the first season of Buffy." This echoing is transparently
clear - the scenes have similar dialogue, the same set of characters
(who are the core characters of the entire series), and the line about
the Earth being doomed is repeated in each. This, however, is
definitely not on the list of what's allowed by NOR.
NOR is a list of things you can't do, not a list of things you can.
Noting that two things are the same when there is no way a reasonable
person could fail to reach the same conclusion after seeing both
sources is not on the list of unacceptable things, thus (unless
prohibited by other policy) it is acceptable.