The 'net opinion' rule appears to be a mere restatement of the established rule that an expert's bare conclusions, unsupported by factual evidence, is inadmissible. It frequently focuses on the failure of the expert to explain a causal connection between the act or incident complained of and the injury or damage allegedly resulting therefrom. Buckelew v. Grossbard, 87 N.J. 512, 524 (1981). For an expert opinion to be admissible at trial it must be based "primarily on facts, data or other expert opinion established by evidence at the trial ...." Id. at 525 (quoting Evid. R. 56(2)(a), currently embodied in N.J.R.E. 703).

In Brun, the court explained its decision to affirm the preclusion of an unqualified expert’s opinions that rely upon complex medical testing in the context of an MRI:

That said, we agree with the judge that, on objection, interpretation of an MRI may be made only by a physician qualified to read such films, and that the MRI report could not be bootstrapped into evidence …. Our conclusion is not dependent on Dr. Corey's status as a chiropractor but on the complexity of MRI interpretations… in State v. Matulewicz, the Court made it clear that it is "the degree of complexity of the procedures utilized in formulating the conclusions expressed in the [expert's] report" that determines its admissibility under the business records exception. 101 N.J. 27, 30 (1985).

… Despite the status of Dr. Meyerson's report, plaintiff repeatedly argues that N.J.R.E. 703 and Macaluso v. Pleskin, 329 N.J. Super. 346 (App. Div.), certif. denied, 165 N.J. 138 (2000), allow the admission of Dr. Corey's testimony, since expert testimony may be based on the opinions of a non-testifying expert. However, we have cautioned that expert testimony should not be used as "a vehicle for the 'wholesale [introduction] of otherwise inadmissible evidence.'" State v. Vandeweaghe, 351 N.J. Super. 467, 481 (App. Div. 2002) (quoting State v. Farthing, 331 N.J. Super. 58, 79 (App. Div.), certif. denied, 165 N.J. 530 (2000), aff'd on other grounds 177 N.J. 229 (2003)).

…In Macaluso, supra, 329 N.J. Super. at 354, upon which defendants rely, a treating chiropractor referred the plaintiff to a neurologist and an orthopedic surgeon, who each ordered diagnostic tests and rendered diagnoses of plaintiff's condition. The chiropractor testified to the diagnoses of the other two doctors, which he deemed "consistent with his own independent findings." Ibid. In holding that there was no error in permitting this testimony, the court relied on N.J.R.E. 703 and cases permitting one expert to testify "to the opinion of a non-testifying expert on which the testifying expert relied in reaching his or her conclusion." Id. at 355. See State v. Alexander, 7 N.J. 585 (1951), cert. denied, 343 U.S. 908, 72 S. Ct. 638, 96 L. Ed. 1326 (1952); Glowacki v. Underwood Mem'l Hosp., 270 N.J. Super. 1, 17 (App. Div. 1994); Blanks v. Murphy, 268 N.J. Super. 152, 162 (App. Div. 1993); Dietzeman v. Peterson, 196 N.J. Super. 96, 101 (Law Div. 1984).

…It appears that Dr. Corey's opinion on the plaintiff's injuries would have been substantially reliant on Dr. Meyerson's interpretation of the MRI films, which was the subject of considerable dispute. Allowing Dr. Corey to testify as to the plaintiff's herniation would have been to permit the admission of the non-admissible hearsay of a non-testifying expert. This attempted circumvention of the Evidence Rules was properly denied by the trial judge. To repeat, this determination is not because the witness was a chiropractor. The same result would have obtained if the witness were a medical doctor unqualified to interpret an MRI.