New York Legal Malpractice Cases Need Clear Causation Standards

Claims against lawyers and law firms continue to grow, as lawyers are increasingly targeted by clients and non-clients alike. This trend shows no sign of slowing.

In any malpractice claim against a law firm, the parties will almost always litigate whether the lawyer has breached the standard of care. But defense counsel will also focus on causation, an issue that can be thorny—and in New York, sometimes dependent on which court hears the case.

This uncertainty reflects a persistent tension in New York legal malpractice law going back nearly two decades. Though most courts have maintained traditional causation standards, others have quietly deviated from established principles of attorney liability. Practitioners need to remain vigilant for these deviations to ensure they remain exceptions, and not the rule.

Roots of Causation

The structure of professional liability claims is straightforward. A plaintiff must prove their lawyer failed to exercise the skill and knowledge commonly possessed by members of the profession and that any failure caused the plaintiff’s damages.

For all negligence claims, causation begins with two core considerations: “but for” and “proximate” cause. “But for” causation ensures the defendant’s conduct was a necessary condition of the harm, while proximate cause limits liability to foreseeable injuries.

In legal malpractice cases, courts have long applied these standards to require that “but for” the lawyer’s conduct, the client would have obtained a more favorable result in the underlying litigation or avoided the claimed loss in the underlying transaction. New York’s Pattern Jury Instructions reflect this standard today.

This is “a high bar to attorney malpractice liability” because it requires “a tight causal relationship” between the client’s injury and the alleged malpractice. In cases involving multifaceted litigation or transactions, measuring causation against the outcome makes sense.

If the lawyer’s conduct and the challenged result are independent, the plaintiff’s claim should fail. Some New York courts, however, have eroded this approach.

Shortchanging Causation

In Barnett v. Schwartz, the plaintiff-client sued its lawyer for malpractice based on advice related to a lease. The plaintiff claimed the defendant failed to disclose that the property was a hazardous waste site.

The defendant appealed a jury verdict against it, challenging the trial court’s jury instruction on causation. In a departure from New York’s rules for attorney liability, the Barnett court held that the plaintiff “need prove only that the defendant-attorney’s negligence was a proximate cause of damages,” but not the only cause.

The court’s reasoning rested on two pillars. First, it found no New York authority “holding that ‘but for’ causation is synonymous with sole proximate cause,” or that legal malpractice cases require a greater degree of causation than others. Second, the court noted that requiring sole causation might undercut New York’s allowance for comparative fault.

The Barnett court didn’t address the gap between its own “a-cause” formulation of causation and the traditional inquiry into whether “a proper defense would have altered the result.”

As the comments to the New York Pattern Jury Instructions recognize, under Barnett, a plaintiff doesn’t have to show that a lawyer’s conduct was dispositive of the outcome; rather, the plaintiff only needs to show the lawyer’s conduct was in the causal mix. By framing “but for” causation as merely a method of proving proximate cause, the court effectively diluted New York’s legal standard for attorney liability.

In the years that followed, several courts have taken a similar shortcut to liability for lawyers. For example, in Utica Cutlery Co. v. Hiscock & Barclay, LLP, the court relied on Barnett to deny summary judgment, holding that a legal malpractice plaintiff must establish that the defendant was a proximate cause of the plaintiff’s damages, but not necessarily the only cause.

Similarly, in N.Y.S. Workers’ Comp. Bd. v. Program Risk Mgmt., Inc., the court leaned into Barnett’s framework, holding that the “‘but for’ standard is not synonymous” with sole causation. Such decisions reflect Barnett’s influence on how some courts and litigants connect the dots between a lawyer’s actions and a client’s harm.

Holding the Line

Most courts, however, haven’t embraced Barnett’s shortcut. For example, in Joseph DelGreco & Co., a furniture seller sued its law firm after the firm allegedly failed to ensure an interest payment was made at closing, triggering a default on a promissory note.

The plaintiff lost an arbitration and was ordered to pay over $4.5 million. In the follow-on case against its counsel, the plaintiff argued that it only needed to show that the attorney’s negligence was “a proximate cause” of its previous loss. The DelGreco court, however, rejected this argument, applying the traditional “but for” standard and holding that, given the “abundant other—and more momentous—bases for DelGreco’s default,” the plaintiff couldn’t establish causation.

Similarly, the court in Dawson v. Schoenberg sidelined Barnett, holding that the plaintiff must show that his conviction resulted from the attorney’s errors rather than his own guilt. Barnett’s causation holding still hasn’t been addressed by New York’s Court of Appeals.

Such decisions show that many courts remain committed to New York’s traditional framework for attorney liability. They also reveal an uneven application of causation standards across New York, undermining the predictability that is critical to litigation about professional standards.

Pushing for Clarity

While Barnett remains an outlier, its diluted approach continues to pull legal malpractice cases outside settled frameworks. The practical consequences of this mismatch are significant. Courts may deny motions to dismiss even where causation is facially attenuated.

At summary judgment, courts may hesitate to resolve causation questions, even where the issue is not appropriate for a jury. And jury instructions incorporating Barnett’s “a-cause” standard will produce outcomes different from instructions based on a standard of direct dependence.

These distinctions affect both plaintiffs and defendants in predictably unpredictable ways. Until the Court of Appeals clarifies this issue, courts should treat Barnett as the anomaly that it is—and practitioners should push to define causation in legal malpractice cases with precision.

This article does not necessarily reflect the opinion of Bloomberg Industry Group, Inc., the publisher of Bloomberg Law, Bloomberg Tax, and Bloomberg Government, or its owners.

Author Information

Alejandro Cruz is a partner in the litigation department at Patterson Belknap.

Kabir Hashmi is an associate in the litigation department at Patterson Belknap.

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