Unfortunately, we get asked this question way too often. Attorney either represented the abusive litigant in an action or filed against the litigant. Either way attorney gets dragged into the web of the malpractice claimant, who may have filed against every judge and state or federal official.
Although the case is clearly frivolous, attorney needs to let attorney malpractice insurance carrier know. By not letting the carrier know, attorney may open up defenses the malpractice carrier might use to deny coverage on other claims.
Best advice is to notify the malpractice carrier promptly and discuss with the claims department how to best dispose of the case.