OK, it is true that if one rebukes someone for the first time or first couple of times(maybe) he has to be careful not to insult the person. If s(he) does not listen, it is halachically mutar to get sharp-tongued at later points in time. The issur of insulting or halbonas panim does not apply to a mumar (even le’teavon). The lady was allowed to use sharp tems while talking to the second lady. The second lady was not allowed to repeat the sharp words to Skiaddict. So, yes, Yichusdic, one has to know the Halochos about these things and oppose the violations in the proper way.
MiddlePath, how about executing or flogging ba’alei aveira? In other words, you have to know what “darkeya darkei noam” means.