1. "Qualified" Is Narrower Than It Sounds
Federal Rule of Evidence 702 requires that a witness be "qualified as an expert by knowledge, skill, experience, training, or education" before their opinion is admissible at all — before the court even reaches whether the methodology is reliable. Attorneys retaining an expert tend to check this box at the credential level: does this person have the right degree, the right board certification, the right professional letters after their name. Courts check it at a narrower level: does this person have specific, demonstrable experience with the exact subject matter of the opinion they're being asked to give.
That gap is where a well-credentialed expert still gets excluded. Below are three federal cases from the last several years where it happened, with the specific reasoning courts gave.
2. Adjacent Expertise Is Not the Same Expertise
In Roe v. FCA US LLC, 42 F.4th 1175 (10th Cir. 2022), a products-liability case over a vehicle shifter assembly, the plaintiff's proposed expert was excluded from testifying about a design defect in the shifter because — despite an engineering background — he had no "experience or training in the design of a shifter or transmission" and had never worked for an automotive component supplier. A second proposed expert in the same case was excluded from opining on the effectiveness of an out-of-park alarm for the identical reason: no experience, training, or published scholarship specific to out-of-park alarms.
The same pattern shows up in firearms litigation: in Guay v. Sig Sauer, Inc., 610 F. Supp. 3d 423 (D.N.H. 2022), a proposed expert was excluded from offering an opinion on a manufacturing defect because he had no experience or training in firearms manufacturing specifically — general firearms knowledge was not enough.
3. The Medical-Expert Version of the Same Trap
The narrowness cuts just as sharply in medical cases, where it's easy to assume any physician can speak to any clinical question. In Godreau-Rivera v. Coloplast Corp., 598 F. Supp. 3d 196 (D. Del. 2022), a medical device case, the court excluded three separate physician experts on qualifications grounds: one was not permitted to testify about what testing a device manufacturer should have performed because that specific competency wasn't established; a second was excluded from opining on the adequacy of product warning language for lacking experience with product labeling and regulatory standards specifically; a third — a physician, but not a toxicologist — was excluded from testifying on the toxicity of a device material for exactly that reason. Being a qualified, practicing physician did not establish qualification to speak to those three narrower questions.
4. A Pre-Retention Checklist
Before retaining an expert — or listing your own credentials as an expert — the question isn't "is this person qualified in their field," it's "is this person qualified on this exact issue." A few concrete questions that map directly onto the case law above:
- Does their direct hands-on experience cover the specific product, procedure, methodology, or defect type at issue — not just the general category it falls under?
- Have they published, been trained, or worked professionally on this specific sub-topic, or only on the broader field around it?
- If the case turns on a specific technical question (toxicity, a specific mechanical component, a specific regulatory standard), does their background actually reach that question, or stop one level short of it?
- Have they been excluded on qualifications grounds in a prior case? Ask directly — a pattern of exclusion on the same narrow-qualification issue is exactly what opposing counsel will find in discovery if you don't ask first.
None of this replaces the reliability prong of Rule 702 — methodology still has to hold up separately. But qualifications is usually the first door a challenge tries, because it's often the easiest one to win: courts don't have to evaluate a methodology's scientific merit to conclude that a witness simply never worked in the specific area they're being asked to testify about.