SIGNIFICANT CASE SUMMARY
New Jersey Case Summary
Weissman v. Li
New Jersey Superior Court, Appellate Division
No. A-2213-22
Decided: December 5, 2025
In medical malpractice action, the Appellate Division upheld the Trial Court’s Order that excluded the opinions of Plaintiff’s expert on medical causation, ruling that his opinion on causation was merely a net opinion.
Background
The Plaintiff, who was a patient that underwent a spinal surgical procedure known as a minimally invasive lumbar decompression (“MILD”), appealed the Trial Court’s Order granting summary judgment to Defendants. Plaintiff argued that the doctor that performed the surgery deviated from medical standards of care, causing a nerve injury that directly produced leg and foot pain. Even after a subsequent surgery that improved his condition, Plaintiff still had to walk with a cane. Plaintiff filed a medical malpractice action against the doctor, medical center and other medical providers.
Plaintiff relied on a single liability expert, a board-certified anesthesiologist and pain management specialist, on the issue of medical causation. Defendant moved to exclude the opinions of the liability expert. The Trial Court granted the Defendant’s Motion for two reasons. First, at his deposition, the expert agreed with defense counsel’s question that he would “defer to a neurologist” on whether the surgery caused Plaintiff to experience symptoms. The Court treated this admission as a concession that he was unqualified to opine on causation. Second, the Court barred his testimony on causation because his expert report conveyed net opinions on the subject. After excluding the expert, the Court then denied Plaintiff’s request to extend discovery to enable him to present a neurologist as a causation expert. Plaintiff appealed.
Holding
On appeal, the Plaintiff argued that the Trial Court erred in excluding his expert and in granting summary judgment because the expert was qualified to testify on causation, and his opinion on causation was not a net opinion. The Appellate Division disagreed with Plaintiff’s argument. The Court examined the proper judicial interpretation of the term “defer” by an expert witness and found that there were split outcomes, and thus the issue is highly contextual. The Court refused to endorse a blanket rule and declined to rest its analysis on the alleged concession. Instead, the Court turned to the Lower Court’s second basis for barring the expert testimony – the net opinion doctrine. The Court found no error on the part of the Motion Judge in concluding that the expert did not sufficiently present the “why and wherefore” required under the net opinion doctrine. The critical shortcoming in the expert’s report was that it did not explain anatomically the causal mechanism as to how the MILD procedure produced Plaintiff’s symptoms. Thus, the Appellate Division sustained the Motion Judge’s ruling on the net opinion doctrine and affirmed the entry of summary judgment.
Questions about this case can be directed to Nick Stolte at .856.334.0415 ext. 8925 or nstolte@tthlaw.com.