Mostly correct. There are a few technical edge cases where it might not be, but not worth worrying about.
For this reason it would actually be a bad idea to separate downvote from rep. The current mechanism is correct, except for the biased icon on the UI.
I have created a github issue a while back and the discussion included whether the UI should tell voters how to vote (I think not): https://github.com/steemit/steemit.com/issues/215