Defending Professional Negligence Claims After Moore: Locking the Plaintiff’s Expert and Winning Causation at Summary Judgment

This session shows how to confine the plaintiff’s standard-of-care expert to the four corners of the expert report in legal malpractice and other professional negligence cases. Attendees will learn how the December 1, 2023 amendment to Federal Rule of Evidence 702 places the burden of proof on the side offering the expert, and how to combine that amendment with Rule 37(c)(1) to exclude opinions that were never disclosed or are poorly supported. The session also covers how New York’s state-court disclosure and admissibility rules create parallel opportunities to lock in and exclude the plaintiff’s expert. Attendees will leave with a deposition framework and a motion sequencing strategy they can apply in both federal and state court.

This session shows defense attorneys how to win legal malpractice cases on causation at the summary judgment stage using the case-within-a-case doctrine. It covers New York’s demanding “but for” causation standard, how to expose gaps and speculation in the plaintiff’s expert causation opinions, and how to use the collectibility doctrine as an independent ground for dismissal. It also explains the meaningful differences in causation rules between litigation and transactional malpractice claims, addresses parallel causation defenses in accountant liability cases, and lays out a concrete motion architecture supported by controlling and persuasive authority through 2024–2025.