Triable Issues of Fact in a Medical Malpractice Case: When Expert Opinions Are Too Speculative

Key Takeaways

• In Severino v Weller, the First Department divided over whether the plaintiffs’ expert opinions raised triable issues of fact; the dissent would have granted summary judgment to the doctor and hospital.
• The dissent’s framework is black-letter law: an expert opinion that is speculative or unsupported by any evidentiary foundation has no probative force and cannot defeat summary judgment.
• A plaintiff’s expert must demonstrate a nexus between the alleged malpractice and the harm, and must address the defense expert’s specific assertions on negligence and causation.
• The same speculative-expert analysis appears throughout New York personal injury and no-fault practice, from serious injury motions to peer review battles.

A note on posture: the quoted language below comes from the dissent, which lost the vote — the majority allowed the claims to proceed. The dissent matters anyway, because it collects the controlling Court of Appeals and First Department authority on when expert opinions are too speculative to create a triable issue of fact.

The Decision

Severino v Weller, 2017 NY Slip Op 01325 (1st Dept. 2017)

This is from the dissent which would have granted summary judgment to the doctor and the hospital. The statement of law is interesting and dare I say useful when looking at healthcare professionals’ affirmation:

“Generally, “the opinion of a qualified expert that a plaintiff’s injuries were caused by a deviation from relevant industry standards would preclude a grant of summary judgment in favor [*5]of the defendants” (Diaz v New York Downtown Hosp., 99 NY2d 542, 544 ). However, a plaintiff’s expert’s opinion “must demonstrate the requisite nexus between the malpractice allegedly committed’ and the harm suffered” (Dallas—Stephenson v Waisman, 39 AD3d 303, 307 ). If “the expert’s ultimate assertions are speculative or unsupported by any evidentiary foundation … the opinion should be given no probative force and is insufficient to withstand summary judgment” (Diaz, 99 NY2d at 544; Giampa v Marvin L. Shelton, M.D., P.C., 67 AD3d 439 ). Further, the plaintiff’s expert must address the specific assertions of the defendant’s expert with respect to negligence and causation (see Foster-Sturrup, 95 AD3d at 728-729). Here, the opinions of plaintiffs’ experts, submitted in opposition to defendants’ prima facie showing that the injury sustained by Mr. Severino was the result of an unpredictable and unpreventable respiratory arrest, were based on supposition and hindsight, and were unsupported by the proof, and were therefore insufficient to raise a material issue of fact (see Manuel H. v Landsberger, 138 AD3d 490 , lv denied 28 NY3d 909 ; Foster-Sturrup, 95 AD3d at 728; Fernandez v Moskowitz, 85 AD3d 566, 568 ; Brown v Bauman, 42 AD3d 390, 392 ).”

The Legal Framework: Expert Proof and Summary Judgment in Medical Malpractice

New York medical malpractice motions follow a familiar choreography under CPLR 3212. The defendant physician or hospital moves first, typically with an expert affirmation establishing prima facie that the care did not depart from accepted practice or that any departure did not cause the injury. The burden then shifts to the plaintiff to raise a triable issue of fact — almost always through a competing expert.

The dissent’s passage maps the three hurdles that competing expert must clear:

1. Qualification and substance. A qualified expert’s opinion that the injuries were caused by a deviation from accepted standards will ordinarily defeat summary judgment (Diaz v New York Downtown Hosp.).
2. Causal nexus. The opinion must connect the specific alleged malpractice to the specific harm suffered (Dallas-Stephenson v Waisman). A departure floating free of causation proves nothing.
3. Foundation and engagement. Assertions that are speculative or unsupported by the record get no probative force, and the expert must answer the defense expert’s specific points on negligence and causation rather than talk past them (Foster-Sturrup).

In Severino itself, the dissenters would have held that the plaintiffs’ experts failed the third hurdle — opinions “based on supposition and hindsight” against a defense showing that the respiratory arrest was unpredictable and unpreventable. The majority saw enough to let a jury decide, which is precisely why the case is a useful study in how thin the line between “speculative” and “triable” can be.

Why This Matters Beyond Med Mal

For practitioners, the speculative-expert doctrine is not confined to malpractice. The same analysis governs serious injury threshold motions, where defense examiners and treating doctors trade affirmations about causation and pre-existing conditions, and it echoes through no-fault practice, where a peer review or rebuttal that ignores the opposing rationale meets the same fate as the experts in Severino’s dissent.

For plaintiffs, the drafting lesson is to make the expert work through the record: tie each departure to a mechanism of injury, cite the chart, and respond point-by-point to the defense expert. For defendants, the lesson is to frame the motion so that any opposition not anchored in the record can be attacked as supposition and hindsight — and to remember that even a strong attack may only persuade the dissent.

Practice Pointers

• Have the expert quote and engage the opposing expert’s specific assertions; courts repeatedly fault affirmations that fail to “address the specific assertions” of the other side.
• Anchor every causation opinion in record evidence — deposition testimony, chart entries, imaging — because “unsupported by any evidentiary foundation” is the kiss of death.
• Watch for hindsight reasoning: an opinion that works backward from the bad outcome is the textbook example of speculation.
• Divided decisions like Severino are leverage in settlement discussions; a two-justice dissent on the expert proof signals genuine appellate risk for both sides.

Related Resources

• Expert competency requirements for medical malpractice testimony
• Foundation requirements for medical malpractice expert testimony
• How experts establish standard of care in specific practice areas
• Expert witness qualifications in New York medical malpractice cases
• Pre-existing injuries in New York personal injury cases — the firm’s cluster hub on injury causation
• The firm’s Legal Encyclopedia
• Personal Injury practice page
• New York No-Fault Insurance Law

Frequently Asked Questions

What is a triable issue of fact in a medical malpractice case?

It is a genuine factual dispute — usually between qualified experts on departure from accepted practice and causation — that requires a jury trial. Under CPLR 3212, if the plaintiff’s expert raises such a dispute with a properly founded opinion, the defendant’s summary judgment motion must be denied.

When is an expert opinion too speculative to defeat summary judgment?

When its ultimate assertions are speculative or unsupported by any evidentiary foundation. New York courts give such opinions no probative force — opinions built on supposition and hindsight, or that fail to address the defense expert’s specific points, cannot raise a triable issue of fact.

What must a plaintiff’s expert show to overcome a defense motion in a malpractice case?

Three things: a qualified opinion that the care deviated from accepted standards, a demonstrated nexus between that deviation and the harm suffered, and a record-based response to the specific assertions of the defendant’s expert on both negligence and causation.