15 Attorneys Share Their Expert Witness Horror Stories

In most instances experts make great witnesses. They are usually personable, have good credentials, and have at least some litigation experience. Still, there’s always the possibility that something could go wrong, and an expert can quickly become a liability. Since one of best ways to avoid a problem is by learning from the experiences of others, we

Expert Horror Stories

ByMehjabeen Rahman, J.D.


Published on January 12, 2016


Updated onJune 23, 2020

Expert Horror Stories

In most instances experts make great witnesses. They are usually personable, have good credentials, and have at least some litigation experience. Still, there’s always the possibility that something could go wrong, and an expert can quickly become a liability. Since one of best ways to avoid a problem is by learning from the experiences of others, we reached out and compiled a list of the worst experiences with expert witnesses both in and out of the courtroom. A special thanks to the attorneys who shared these experiences with us!

Improper Courtroom Demeanor

Even when it seems you have the perfect expert witness, you can be blindsided by unexpected circumstances during depositions or worse- trial. Even when an expert’s experience, credentials and appearance all seem to check out, it is important to keep in mind the possibility of your expert witness “going off script,” leading to unfavorable consequences for your case. There are a number of reasons an expert may do this- anything from excited nerves and inflated egos, to a desire to please the attorney and the jury- but no matter the reason, the most important thing you can do as the attorney is to go over these “worst case scenarios” with your expert witness to avoid any surprises.

Susan Cox – Edenfield, Cox, Bruce & Classens

“In a medical malpractice case, our expert was a Harvard-educated, well-credentialed expert who literally “wrote the book” on his topic. However, he was also an arrogant jerk – rude, demanding, and a total pain in the ass. As we approached the trial, I truly dreaded my interactions with him and could not wait to get the case over with so that I would never have to speak to him again. He did what we asked of him – he came and testified for our side and I thought, based on his credentials, that he was an impressive witness. However, his personality was still the same [at trial] and we lost the case. The judge allowed us to talk to the jury after the verdict and it was pretty clear the jury hated him, too – he might have had prestigious credentials, but they didn’t like his arrogance and felt that he was condescending toward the defendant doctor. Instead of persuading the jury, he ended up generating sympathy for the defendant. The take-away from this experience? If I don’t like the witness, I should not expect the jury to like him or her, either.”

Bruce James – Whitaker Chalk Swindle & Schwartz PLLC

“Our valuation expert was well qualified and well educated. However, once on the stand and never before during deposition or pre-trial preparation, he decided to endear himself to the jury by becoming a comedian of sorts. While all laughed, it obviously hurt his credibility when compared to the seriousness of the defendants’ expert witnesses. While our liability questions were answered favorably, our damages questions were answered extremely low, in fact, lower than the last settlement offer from the defendants. As to steps taken to avoid this issue in the future, it is a 10-minute lecture on not being a comedian, wise guy or know-it-all in the courtroom to insure that the Judge and jury are convinced our evidence and witnesses are rock-solid serious about the facts and their expert opinions. Our motto is ‘no humor in the trial of a case!’ This is serious business.”

Inexperienced Witnesses

Given that experts can be vulnerable to many of the same pressures as any other witness on the stand, it is crucial to minimize the potential for problems stemming from inexperience in a courtroom setting. Because of the nature of expert witnesses and their testimony, it is easy to forget that not all experts have litigation experience. Overlooking or failing to discuss this fact can be quite detrimental to your case, especially in instances where the witness is not deposed before trial, since you don’t have a chance to see how your witness will handle him or herself when questioned by opposing counsel.

Diane PumphreyWilkins Patterson Smith Pumphrey & Doty, P.A.

My worst experience with an expert was one who was a lion in trial preparation but at trial became a lamb. I don’t think he made an effective advocate at trial. He was the causation expert and plaintiffs got a verdict in their favor. The plaintiff’s attorney did not depose him before trial and I think this was his first experience as an expert in this arena. Since he was not deposed I did not know how he would handle being cross-examined. I have since asked experts about their trial experience and discreetly checked them out with defense counsel who used them at trial.”

Lauren EllermanFrith & Ellerman, PC

“I once had an oral surgery expert who had been designated to speak on standard of care, and had signed no less than 2 documents during his review of the case outlining how the defendants violated the standard of care and were negligent. Yet he testified in a deposition that he had no opinions on how the defendant’s actions were or were not negligent prior to the deposition. [The expert] went on to say I had never asked him to render or offer any such opinions until that morning and because he felt trapped by my questioning, he felt pressured into offering an opinion. This despite signed statements to the contrary dated 9 months earlier. I non-suited my case half way through the deposition so the deposition would end. I now send another copy of all written and signed documents to the doctor when I schedule the deposition as well as meet face to face to discuss their opinions weeks before the deposition date.”

Peter HobaicaPeter M. Hobaica, LLC

“In a wrongful death case involving the failure to obtain proper pre-op clearance, a cardiac expert was initially retained by the firm who referred the file to me. At trial, the expert turned out to be a nightmare. He still supported the case, but changed his entire theory of negligence literally on the steps of the courthouse! We had taken positions in our disclosures which he would no longer support. The defense cross-examination was devastating and I was not able to restore his credibility on redirect. We lost the case. Since then, I NEVER rely upon another’s expert. I ALWAYS retain my own after fully vetting their credentials and their opinions. I seek their advice on how the case might be defended and, I ALWAYS obtain from the expert a written opinion letter after discussing the merits with them.”

Michael MosscropFranklin, Gringer & Cohen, P.C.

“My worst experience with an expert witness concerned a misdiagnosis of precancerous cells in the uterus. All went well on direct examination. However, during cross-examination my expert had testified that one of the things he did to prepare for his testimony was to “google” the condition that was the subject of the entire lawsuit. Let’s just say the defense attorney had a ball with him after that and my expert lost all credibility with the jury. That is one of the worst things an expert witness can say on the stand because the judge reminds the jurors not look up the medical conditions at issue in the case on Google or on the internet- one of the reasons being that there is a lot of wrong information on the web. I had prepared that expert witness for days leading up to the trial, but did not take it upon myself to advise him not to discuss “google” or the internet. Ever since that experience, I specifically advise my experts to never mention Google or the internet when discussing how the expert prepared for his or her testimony. You would think this is obvious, but my experience proved otherwise. Experts, no matter how experienced, need to be properly prepared with respect to every single aspect of their testimony, even the most obvious aspects.”

Credibility, Credentials, and Cost

When preparing for trial or deposition, don’t assume anything and be as explicit as possible about the information you request of your expert in terms of their credentials, credibility, and cost. The eve of when expert disclosures are due is not the time to find out that your expert does not have a college degree. Perhaps have a checklist or questionnaire prepared for your first meeting with your expert so that preliminary questions aren’t accidentally overlooked. Disputes over billing can be avoided by discussing them up front. Whether you are asking your expert to review materials, conduct a study or just do some preliminary research, be sure to discuss costs first so you are not caught by surprise. Also, failing to keep a log of all tasks and correspondences can lead to miscommunication over what was expected of the expert. That will undoubtedly have an effect on the trial preparation of your case or even worse, the trial itself.


“The worst experience was hiring an expert in a securities fraud case who failed to disclose that he himself was then under investigation for committing securities fraud. We wound up terminating him before he was charged (which is when we learned of the investigation), but in any event had to pay a significant amount of money for work product that was ultimately useless. The lesson from that experience seems basic, but is probably worth reminding lawyers: always ask potential experts whether they have ever been accused of misconduct or are under investigation before retaining them.”

Timothy MonseesMonsees & Mayer

“The most disastrous experience was when an expert refused to testify further at a time very close to trial, because he refused to disclose financial and earnings data that had been requested by the defense, and which had been ordered to be produced by the court. That left me without an expert too close to trial to retain a suitable replacement.”


“One bad experience was retaining an expert to provide some fairly technical analysis only to later learn, when it became necessary to finalize his expert disclosures, that he had no college degree. Again, the lesson seems basic but it’s important: get a full CV and ask questions about qualifications on the front end.”

Scott CooperSchmidt Kramer, PC

“One of the worst experiences was when my expert, the only treating doctor, attended a medical school in Mexico and attempted to say that he chose that university as opposed to a medical school in the United States. It impacted the case because the jury clearly did not believe that he voluntarily chose a foreign medical school. From then on, I always use experts that went to American medical schools or have an independent expert do an examination and testify.”

Jeff MilmanHodes, Milman & Liebeck LLP

“I once received a bill for over $30,000 for a simple review of minimal materials and two hours testimony. I now go over a budget with my expert. Another instance was having an expert tell me at the deposition that I never sent him certain materials so they are unprepared. We now log everything we send an expert and make sure they review the log prior to their deposition.”

Exceeding the Scope of Testimony

All of these attorneys’ experiences bring one of the most important and fundamental aspects of an expert witness’ testimony to our attention: the need to stay within the scope of their expertise and the questions asked. As soon as an expert witness starts testifying to matters outside the scope of the question asked or the matter at hand, he or she is in dangerous waters, and risks making statements that would be to the detriment of your client’s interest in the case. The importance of keeping statements within the scope of testimony must be stressed to the expert witness.

Ryan Armour – Cassiday Schade LLP

“One problematic issue that has arisen in the past is where there are multiple physician-defendants and our expert is, in private discussion, supportive of our client but critical of one or more of the other physician-defendants. When we encounter these situations, we advise the expert that he or she is only being utilized to testify about the care that our client rendered and/or a very specific aspect of the case, and not to render any opinions about other physicians’ involvement or conduct. Despite our instructions, though, there have been times in which an expert has either (1) disregarded those instructions or (2) was asked difficult questions by another attorney that required the doctor to testify in a way that harmed a codefendant. More often than not, these problems arise because of a physician expert’s wish to be helpful, while also being authoritative and appearing as the paradigmatic expert. While experts are supposed to be authoritative, they are generally retained by attorneys for a very specific purpose. They must be apprised of, and understand their purpose in the litigation, and be prepared to answer questions that fall outside the scope of their review or purpose by saying as much or deferring to other specialties.”

Susan Cox – Edenfield, Cox, Bruce & Classens

“One bad experience involved an expert in a defective seat belt case. The seat belt in question was one of those with the automatic shoulder harness. We had an expert engineer on the defect which caused serious injury to our plaintiff when she was ejected from the car. On deposition, the engineer went beyond the issue of the defect to opine that the entire design was dangerous and to state why he thought so. However, further questioning revealed that while his car did not have this system, the cars his wife and teenage daughter drove did have this system. Bottom line – he didn’t drive a car with an unsafe system, but he let his wife and daughter drive cars with systems he considered unsafe. That deposition was the last time anyone heard from this guy in our case. Be sure to meet with your experts in person and ask all of the potentially embarrassing questions that the other side will be sure to ask before hiring the expert.”

David CohenJones, Skelton & Hochuli, P.L.C.

“Experts must recognize that they are supposed to be objective, and not advocates for the party who retains them. Although not a specific example, profuse advocacy affects the expert’s credibility which adversely affects the case.”

Keeping Up Appearances

Courtroom presentation and etiquette are just as important as the substance of the expert witness’ testimony itself. The need to dress appropriately for court might go without saying… until the expert shows up in flip-flops. A simple discussion of appropriate attire and a dress rehearsal during trial preparation could be the difference between a smooth testimony and a potentially embarrassing or distracting testimony. Unfortunately, it is not possible to predict the future and, of course, sometimes emergencies do happen. The best way to avoid a worst-case scenario is to have extremely open lines of communication, and to stress the importance of accessibility to your expert so you can keep each other apprised of any changes and can plan accordingly.

Chip BentonHall, Booth, Smith, P.C.

“My worst experience with an expert was when my expert was late for court and would not answer his cell phone. When he did show up for court he marched right into to the courtroom violating the rule of sequestration. The judge almost did not let him testify but he was our only expert witness. When he did get to testify he was very soft spoken and often wavered on standard of care issues.”

Richard JaffeJaffe, Hanle, Whisonant & Knight, P.C.

“I was representing a person for capital murder and we believed the crime scene was staged to make it look like a rape/murder and ultimately at trial the prosecution conceded that. We retained an expert pathologist I had prior experience with but shortly before trial he bailed without an explanation and gave us virtually no notice.”

Micah LongoThe Longo Firm, P.A.

“There was an injury case where the treating physician appeared wearing a wrinkled white suit and flip-flops. This blonde-haired shaggy orthopedist looked like he just rolled out of bed after a long night of partying on the beach. The jury never got past his appearance even though he was extremely qualified and gave favorable testimony. Unfortunately, the doctor didn’t care about his appearance which hurt the case. From that case on I make sure my experts are more responsible and understand the need to be on time and respectful to the Court. I always meet with the expert either the night before they testify or the morning before they go on the stand.”

The outcome of cases in which expert testimony is used can and often does rely heavily on the expert’s testimony. However aside from the sheer substance of the testimony, there exist a number of moving parts- the totality of which jurors see. This includes things like the witness’ demeanor, dress, and scope of testimony. In asking a number of attorneys for their top expert witness “horror stories,” we wanted to offer an article that helps attorneys avoid some of the issues that may arise when dealing with expert witnesses. For a helpful checklist that outlines many of the issues in this article, see our deposition preparation checklist as well as our trial preparation checklist.

About the author

Mehjabeen Rahman, J.D.

Mehjabeen Rahman, J.D.

Mehjabeen Rahman, J.D., is a versatile legal professional, currently a Law Graduate at Gutman, Mintz, Baker & Sonnenfeldt. She has been serving as a Staff Writer and Legal Blog Author for the Expert Institute since September 2015, where she conducts expert interviews and writes advisory articles for the legal community.

Her hands-on legal experience includes internships at the Kings County District Attorney's Office in the Special Victims Bureau and the Community Legal Assistance- Law Reform Advocacy Clinic. At the DA's office, Mehjabeen assisted in case preparation and trial observation, and at the Advocacy Clinic, she managed litigation for a Civil Action case and argued pretrial motions. Additionally, she gained experience in criminal defense and motion drafting during her internship at Renfro, Driscoll & Foster, LLP.

Mehjabeen earned her Juris Doctor from Maurice A. Deane School of Law at Hofstra University, where she was a Mock Trial Team member, Clinic Student, and Associate Editor for the Hofstra Labor and Employment Law Journal. Her legal education and practical experiences underscore her expertise in legal research, writing, and trial preparation.

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