On at least two occasions recently, a user (different users) left a totally inappropriate comment only to quickly edit it. In these particular cases the intended recipient was notified and saw the comment as it was prior to being edited.
In both of the cases I'm thinking of, the flagrant violation of "Be Nice" was somewhat mitigated by the fact that the comment was quickly edited. However, it's better that nasty things are not said at all than thinking better of it after the fact.
So, if you get a notification of a comment that would have been flag-worthy had it still existed in the original form, please let a mod know.
If the comment has simply been deleted, just custom-flag the post it was on and ask us to have a look.
If it was edited, please take a screenshot of the message in your inbox so we can see exactly what was said; unfortunately edits to comments are not kept the way edits to questions and answers are. You can ping us in chat or ping any of us in an answer to this question.
You don't need to show us the message publicly, we can open a private chat if you would rather the original message not be seen publicly.