"for civil cases? all the time. Especially, in probate matters. "
So what does it take to prove malpractice? Do lawyers pay malpractice insurance premiums?
I would guess that most malpractice cases are over mistreatment of a client. Lawyers, like a lot of people, think the ultimate betrayal is screwing someone who paid you money to do right by them.
They give those who abuse the power of their office way too much latitude on grounds that they toil for what the legal profession considers slave wages (Nifong makes "only" about 138K). It's really sickening when you think about it.
The critera varies from state to state but generally the test is a "but for the lawyer's actions the client would have prevailed." It is a pretty high test. You have to prove you would have succeeded but for this lawyers conduct.
As for insurance, I don't know of any state that requires malpractice insurance. Most claims that are made on malpractice confuse losing the case screwing up. Remember 1/2 of all civil clients in trial in the courthouse every day are destined to leave unhappy. Malpractice claims generally don't get far.
In this case Nifong would more accuratly be subject to a malicious prosecution claim. (particularly for intentionally witholding exculpatory evidence.)
Of course the state bar may have a victim compensation fund the duke players could make claims against...