Hmmm... Not being American, at points I feel many of the definitions and arguments presented in this thread apply only in the US/North America and a couple of European countries (in particular, central and western countries). Which is perfectly fine btw, especially since the origin of this discussion is indeed a teacher in the US.
Maybe I'm wrong (and if I am, no problems, feel free to correct me) but it feels like many of stuff discussed here kinda breaks apart when you go outside of the regions I mentioned, though perhaps not so much on a pure racial basis (though it definitely is there) but more on a xenophobic basis.
Even on a historical standpoint these concepts kinda get iffy if we go further back than the Transatlantic Slave Trade (we, as a species, have "played" with the concept of slaves for thousands of years).
Though again, this is just me extrapolating the arguments/definitions here presented to a global scale. On a more regional scale, in particular regarding systemic racism, I'd say they fit (depending on the region in question of course). Wouldn't go as far as to make such a blank a statement as the teacher did, but there is definitely a lot of truth to non-whites in NA/Europe having their life be a lot more difficult than it should be "just because".