Whenever we see a rude or offensive post we should flag it to allow appropriate moderation.
Offensive posts can be deleted by community moderation if they gather enough offensive flags.
In case somebody made a rude or offensive edit to another user's post we should not flag this post as rude or offensive because this may lead to negative effects on the original poster's account. Flag for moderator attention instead.
If a user edits their own posts it may be a good idea to just delete the offensive content by an edit if the post was good otherwise. Nevertheless we should let us moderators know about it (e.g. by using a custom flag for moderator attention explaining the issue). When just using an offensive flag it may be easily overlooked and then declined if a later edit removed the offensive or rude content.
It is vital to us to get notice of any user's behavior not welcome in our community. Only then we can take then necessary actions.