No, LdiJ. This is wrong. And that is what I was trying to correct in your earlier post.
Attorneys can in fact be sued by a non-client for malpractice.
It used to be that attorneys were protected from claims filed against them by non-clients, thanks to the doctrine of privity. A privity of contract is a relationship between the parties to a contract that allows them to sue each other but prevents a third party from doing so.
This protection from suit by a third-party is no longer the case in Illinois or in many other states. Whether a malpractice claim can be filed against an attorney by a non-client can depend on if the attorney owed a duty of care to the non-client.
From Pelham v. Griesheimer, 440 NE 2d 96, Ill. Sup. Ct. 1982, the Court said: "We consider that privity is not an indispensable prerequisite to establishing a duty of care between a nonclient and an attorney in a suit for legal malpractice ... The trend in tort law has been to abolish privity of contract (Rozny v. Marmul (1969), 43 Ill. 2d 54) as a prerequisite to establishing a duty."
See also: Greycas, Inc. v. Proud, 826 F. 2d 1560, Court of Appeals, 7th Circuit, 1987, where the Court said that, in Pelham: "[T]he Supreme Court of Illinois discarded the old common law requirement of privity of contract for professional malpractice; so now it is possible for someone who is not the lawyer's (or other professional's) client to sue him for malpractice."
Is what has been described here likely to support a malpractice suit against the ex-wife's attorney? I have no idea. It depends on far more facts than we have been given. It is probably unlikely ... but I would not want to rule out the possibility without knowing more.