I would say that speaking out may be necessary in such a case. What is of the utmost importance, however, is that YOUR motive be proper. If your motive isn't of the soundest kind, then it is very likely that you overstate the fault and communicate it in a way that causes more harm than good.
If upon deep consideration you do believe it best to speak up, then do so with as much goodwill and skill as you can muster, as put forward in bodom's first post above.
Edit, added the word 'harm' above.
Last edited by Reductor
on Fri Jul 01, 2011 11:16 pm, edited 1 time in total.