When you are guilty of malpractice, you run a grave risk if you prepare a defense while continuing to represent the client.
As a lawyer, you are in a fiduciary relationship with your client. You must tell your client if you think you are guilty of malpractice. You must tell enough to give the client the ability to make an informed decision whether to discharge you and hire new attorneys.
Hence the general rule the courts may enforce upon you is:
“Ask and think, but don’t talk! Research whether we are guilty of malpractice, but don’t write about it. Don’t even talk to me about it!
Internal Firm Memo of Law may not be privileged. In Versuslaw, Inc. v. Stoel Rives, LLP, 2005 Wash. App. LEXIS 586 (Wash. App. April 4, 2005) the court held that internal law firm memoranda concerning a possible malpractice claim against the law firm might not be privileged if they were written while the lawyer-client relationship still existed. It makes sense, because of the fiduciary duty to disclose. The next logical extension is saying that lawyers in the firm discussing the possibility of malpractice have no effective work product privilege to prevent disclosure of what was said about the possible conflict of interest between the firm and its client (and maybe even discussions with the insurer are subject to disclosure). The only safe harbor seems to be to get out of the attorney-client relationship, then research and talk about the malpractice possibility.