In Kennedy v. Hall, No. 16-60569, 2017 WL 664041, at *1 (5th Cir. Feb. 17, 2017), the Fifth Circuit affirmed summary judgment for a Mississippi attorney and his law firm in a legal malpractice action applying the “case-within-a-case” doctrine. Mississippi law requires the plaintiff in a malpractice action to prove by a preponderance of the evidence 1) the existence of a lawyer-client relationship, 2) negligence by the lawyer, 3) proximate cause, and 4) injury. To prove proximate cause, the plaintiff must prove a case-within-a-case, that but for the attorney’s negligence the plaintiff would have been successful in the prosecution or defense of the underlying legal action.
In the underlying legal malpractice action, a lender sued the plaintiff for breach of a personal guaranty contract. The lender obtained a large judgment. The plaintiff then sued her defense attorney and his firm, alleging the attorney failed to raise the affirmative defense of setoff for the value of collateral retained by the lender. The district court granted summary judgment to the defendants on grounds that the guaranty contract contained a provision waiving any right of setoff. The Fifth Circuit affirmed, ruling that based on the plaintiff having contractually waived any right to setoff, she could never prove that the attorney’s alleged failure to present the setoff defense proximately caused her any damages.