Oklahoma Expert WitnessesIntroduction:

In January, a federal district court heard a motion to exclude an expert witness in a case involving a family business dispute. See Patel v. Patel, Case No. CIV-17-881-D (W.D. Okla. Jan. 4, 2019).

Of prime significance was the court’s role in addressing expert testimony and the reliability standard that applies under Federal Rule of Evidence (FRE) 702 and the Daubert test. See id., at 1-2.

This article examines the recent ruling with particular emphasis on the court’s view of its function with respect to expert evidence.


The plaintiff in the dispute retained a certified public accountant (CPA) and designated that witness as an expert. See id., at 2. The defendants did not object to the witness’s qualifications, but they did challenge the reliability of the testimony to be given. See id. Two reasons were put forth to sustain their objection.

First, the defense claimed that the accountant’s testimony was unreliable because the expert “had insufficient facts and data to reach any conclusion.” Id.

The second contention advanced by the defendants was that the expert witness’s “methodology is flawed because it is based on unreliable information and assumptions.” Id.

The Court considered both of these arguments and also emphasized the rules it would apply in such instances. See id., at 2-3. Those rules, which are codified in the Supreme Court’s Daubert holding, are iterated by the Tenth Circuit, which states that “[u]nder Rule 702, the district court must satisfy itself that the proposed expert testimony is both reliable and relevant, in that it will assist the trier of fact, before permitting a jury to assess such testimony.

In determining whether expert testimony is admissible, the district court generally must first determine whether the expert is qualified by knowledge, skill, experience, training, or education to render an opinion.

Second, if the expert is sufficiently qualified, the court must determine whether the expert’s opinion is reliable by assessing the underlying reasoning and methodology, as set forth in Daubert.” Id. (quoting U.S. v. Nacchio, 555 F.3d 1234, 1241 (10th Cir. 2009)).

The defense moved to exclude the accountant’s opinion and argued that the testimony lacked “a reliable factual basis” because the witness “utilized recreated records provided by Plaintiff’s son and relied on speculative assumptions.” Id., at 3.

As the court explained, the gist of the defendants’ claim is that the expert evidence is “unreliable because [it is] founded on faulty or incomplete information.” Id.

However, this premise is problematic in the court’s view since the defense acknowledged that important “financial documents are missing or never existed.” Id.

The defendants claimed, moreover, that the parties’ culture relied on informal business practices, and they conceded that “the accountant who prepared the pertinent financial statements…is unavailable as a witness.” Id.

The judge determined that the plaintiff had no other option but to recreate and piece together financial documents in order to establish his burden of proof. See id.

Because of the circumstances, and in consideration of the competing arguments, the court held that the proffered expert’s testimony had “a sufficient basis in the alleged facts of the case,” and the evidence was deemed reliable. Id.

The court believed that the essence of the defendants’ objection to the expert was simply a disagreement with the witness’s conclusions. See id.

According to the judge, such concerns are not acceptable reasons for a court to exclude expert testimony. See id.

As the court makes clear, “Rule 702’s focus ‘must be solely on [scientific] principles and methodology, not on the conclusions that they generate.’” (quoting Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579, 595 (1993)).

The defense arguments were, in the court’s view, more about the weight and credibility of the evidence (which is a jury’s provenance), rather than the reliability of the testimony. See id.


The Oklahoma district judge who heard the request to exclude expert testimony rejected it, deciding that cross examination, and if appropriate, objections at trial would resolve the issues raised by the defendants.

Perhaps the most important takeaways from this case are two-fold.

First, the court emphasized that disagreeing with a conclusion is not grounds to exclude an expert as being unreliable under Daubert and its progeny. See generally id.

Second, the holding expressed that Daubert gives trial courts some flexibility in their gatekeeping function, and that the district court felt it could best assess the expert’s opinion in better context at the trial. See id., at 4-5.