@Ramhound - If a comment explaining a down-vote is retracted, that implies to me that there can be no reason for the down-vote, so of course it should be reversed. If a comment remains valid after further discussion or edits, then the down-vote stands. To down-vote without a reason seems entirely contrary to the intention and spirit of the site.

@JourneymanGeek - Yes, it is related, and I read it before my post, but it seems to address all down-votes, not uncommented ones.