Medical Malpractice ExpertsIntroduction:

In medical malpractice cases, certain elements must be proven by plaintiffs in order to make a recovery, and in most states, those elements must be shown to a degree to even file a complaint. This article reviews such cases and the role of expert witnesses, from the perspective of a professor of surgery, who is a licensed M.D. and also has a legal education (J.D.).


Dr. Darryl S. Weiman is a professor of surgery at the University of Tennessee Health Science Center, and as a person with both legal and medical expertise, is uniquely situated to offer insight into the issues regarding medical expert witnesses and the litigation they take part in.  He provides guidance for attorneys on a host of issues, and his primary emphasis concerns the base of a medical malpractice claim: whether or not the standard of care has been violated. See Darryl S. Weiman, “The Standard of Care,” Huffington Post, Dec. 19, 2017, at (last visited Dec. 20, 2017).

Dr. Weiman explains the general nature of medical malpractice claims, expressing that “[i]n order to prevail in a medical malpractice action, the plaintiff must show, by a preponderance of evidence standard, that the defendant owed a duty of care to the plaintiff, the defendant was negligent in providing that care, the plaintiff was injured, and the legal cause of the injuries was the negligent care. All four of these elements must be shown for the plaintiff to win.” Id.

In Colorado, Florida, and many other states, a complaint alleging medical malpractice cannot be filed without expert witness involvement. See, e.g., Heather Morton, “Medical Liability/Malpractice Merit Affidavits And Expert Witnesses,” National Conference of State Legislatures, Jun. 24, 2014, at (last visited Dec. 20, 2017). Over 25 states require what is called a “merit affidavit,” or certificate of merit,” which generally means that a complaint must be accompanied by a medical expert witness’s statement that reasonable grounds exist to believe that malpractice occurred and the standard of care was violated. See id.

One important issue mentioned by Dr. Weiman in medical malpractice litigation is what to do if a false diagnosis occurs. There are false positives and negatives in diagnostic testing, he explains: human and/or digital error occur with some frequency. See David S. Weiman, supra. However, a false diagnosis does not necessarily mean doom for a defendant in a lawsuit. For instance, “If the provider can show that [he or she] considered these types of conditions and…took steps to make the diagnosis, then [he or she] will likely win even if the diagnosis is missed.” Id. This is important for attorneys to be aware of, and expert witnesses play a clear role here—they can discuss the whys and hows of false diagnoses and explain to factfinders whether the standard of care was violated or not, regardless of an incorrect diagnosis. Some litigators have mistakenly assumed that if they can demonstrate a false diagnosis, they will automatically prevail, but as Dr. Weiman has articulated, focusing on whether the proper steps were followed is the key, and making that assumption, without having a high-quality medical expert to back up a claim regarding the standard of care, can result in an unexpected loss for plaintiffs. See, e.g., id.

When it comes to establishing the standard of care and whether or not it was violated, laypersons do not have the knowledge to speak to this matter. According to Dr. Weiman, “Expert testimony is required because most people do not have the knowledge or experience needed to make decisions on standards of care by themselves.” Id. The standard of care is something that most states define in their statutes on medical malpractice claims, but the interpretation of those definitions and explanations of whether such standards were adhered to is a matter for experts. See id.

Updates in the medical field have been made with respect to several injuries and/or illnesses. Specifically, “[i]n medical practice, there are many conditions which now have recommendations for care and treatment. These recommendations come from committees comprised of recognized experts in the field.” Id. However, again, Dr. Weiman provides invaluable insight to attorneys, when he explains that “I was at a lecture for continuing legal education where a well-known plaintiff’s attorney stated that, as far as he was concerned, the ‘best practices’ paradigms recommended by these committees were now the “standards of care” and any health care provider who did not follow the paradigms was committing medical malpractice. He was wrong. Most, if not all, of the publicized treatment recommendations have a disclaimer which recognizes that it is up to the treating clinician to decide[] on the proper care of a particular patient. The law has not changed; the standard of care is still the care that would be provided by a reasonable physician who is faced with the same or similar circumstances. If a reasonable clinician would not have followed the committee’s recommendations, then the standard of care may still have been met.” Id.

If a prominent attorney in the field could misunderstand the elements necessary to establish a medical malpractice action, certainly, this underscores the value of Dr. Weiman’s guidance on the matter. More importantly, it makes clear how critical expert witnesses are in such cases, as they are the ones who can take even written guidelines compiled by their peers and explain why those guidelines may or may not apply in a specific instance. See id.

In addition to admonishing plaintiff’s attorneys on what pitfalls to look out for and helping defense attorneys become acquainted with successful ways of defeating cases of this nature, Dr. Weiman expresses a deep understanding of how defense attorneys may best address a given plaintiff’s expert witnesses on cross-examination. See id. Weiman notes that common defense strategies often include factors such as how much an expert witness is being compensated for giving testimony at depositions and trial, in an effort to demonstrate bias or a lack of credibility. See, e.g., id.

However, Dr. Weiman goes a step further—he suggests that rather than simply sticking to the commonly-followed routine, attorneys in malpractice cases try to defeat opposing experts by showing the jury that the witness at issue is not really an expert at all. See id. For example, “[t]his can be done by exposing weaknesses in the expert’s curriculum vitae. A national survey of 2.6 million resumes done in 2003 showed that 41 percent lied about their work experience and 23 percent lied about their credentials or licenses. A surprising 41 percent lied about their education.” Id.


Most litigators in the medical liability field understand that by taking on a case, regardless of whether they’re plaintiff or defense advocates, they will be involved in a battle of the experts. However, Dr. Weiman’s status as both a person with a legal and medical background, as well as an instructor for continuing legal education, allows him to provide new insights into some of the nuances involved in such cases and the role of expert witnesses. As he concludes, “There are few trial lawyers that can show superior knowledge to the expert in the medical field under discussion. After all, they are lawyers and it is unlikely they have ever treated an actual patient.” Id. Taking this perspective into account and utilizing experts to help out, particularly in “what if” or “if/then” scenarios, can assist attorneys on both sides in achieving the outcome their client is hoping to see.