I'm tossing this out unchecked but I believe that Jesus' and any of the accounts of others in the NT using harsh words were always directed at those who were contemplating murder, planning murder, or engaged in theft. Check out the exchange that Jesus has with the Syrophoenician woman in Mark 7:24-30. It is the only example I can find where Jesus is using harsh words to a common person.
I would argue that, other than the above mentioned, most of Jesus' harsh words were directed at those in power, like the Pharisees, which, to be fair to you, is pretty much the same as directing His words only at those who were contemplating murder or engaged in theft.
DrJ and I discussed this in further posts on this thread. Read through them and see what you think.
The Syrophoenician woman does seem to qualify as use of "harsh words" and perhaps "use of abusive words." I've heard some argue that dogs should be translated "puppies," and I agree that that softens the exchange considerably. "Don't give children's food to puppies."