What Happens if My Lawyer Made a Mistake and Was Representing my Confidential Informant at the Same Time?

This scenario amounts to a huge conflict of interest and this typically requires the lawyer to withdraw from representation from both parties. The problem can arise even through no fault of the lawyer. The problem can arise as follows: Let’s say a private criminal defense lawyer (or public defender) represents a number of individuals on pending charges some of which may be drug related. If one of his clients decides to work as an informant (to lessen his charges), he may be asked to go out and assist on an investigation by wearing a body wire and visiting the home of people who may also be represented by the same lawyer. Obviously the lawyer is not consulted beforehand because such matters are treated confidentially by the police and the informant is sworn to secrecy. This can obviously be a common problem in small towns but this also arises in large cities as well. A defense lawyer usually does not hear any details about what his or her informant client is doing, but when his other clients are arrested the lawyer may become suspicious. But while the lawyer may become suspicious, he or she is not able to ask too many questions either, and the lawyers suspicions may not be confirmed for several months. When it becomes apparent to the defense lawyer that this problem has arisen, he or she cannot ethically represent either party and must withdraw from representation. Sometimes, the lawyer is forbidden from explaining why he or she must withdraw, and may leave all parties without a clear idea of what the problem was.

See here for more common questions about informants.