Posted by: John Day on Jan 1, 2021

Journal Issue Date: Jan-Feb 2021

Journal Name: Vol. 57 No. 1

Not every Tennessee health care liability case requires expert testimony on the issue of whether the defendant violated the standard of care. An expert is not required when “common knowledge” exception negates the need for it.

The common knowledge exception applies in a small percentage of health care liability cases. The most colorful early description of the principle advises “when medical negligence is, so to speak, as plain as a fly floating in a bowl of buttermilk, an exception to that general rule is permitted and the doctrine may apply; such as when a sponge is left in the gut; the eye cut when performing an appendectomy.”1

One’s mind’s eye quickly imagines a verdant lucilia sericata2 doing the backstroke midway across a white soup bowl brimming with Organic Valley pasteurized buttermilk. Yes, there it is, standing out as plain as the moon pasted in the sky on a cloudless Winter Solstice. As glaringly obvious as a sliver of broccoli jammed between your lateral incisor and cuspid at full smile. As striking as a set of Kocher Intestinal STR 10.5-inch forceps in the open abdomen of a 140-pound, 5-foot, 6-inch marathoner. As evident as … you get the point. 

While colorful, the “flying floating in a bowl of buttermilk” test does not provide much guidance on when a plaintiff can avoid the trouble and expense of an expert on the standard-of-care issue in health care liability litigation. The recent decision in Jackson v. Burrell3 helps fill in the gap. After reviewing the history of the law in Tennessee (and around the nation) on the subject, the court announced the following test of when an expert would be required:

…whether the alleged negligent conduct involved technical or specialized knowledge of a medical procedure or a patient’s medical condition or whether the alleged negligent conduct involved medical decision-making — such as determining the type of treatment or procedure to perform or the type of equipment or medicine to use. If so, then expert proof would be necessary. As Professor [Joseph H.] King has suggested, this inquiry might be phrased as whether ‘[t]he specific decision making by the health care provider ... involve[d] the exercise of uniquely professional medical skills, a deliberate balancing of medical risks and benefits, or the exercise of therapeutic judgment.’4

It then applied the test to the facts of the case, holding that allegations that no expert testimony was necessary to demonstrate that the owner of a day spa was negligent in its training, supervision and retention of a licensed massage therapist who allegedly sexually assaulted plaintiff (and other people over the years) during a therapeutic massage.5 The court explained that such a claim did not involve the need for expert testimony about “different types of massage, proper techniques for performing a type of massage, or other specialized knowledge that an expert in the massage industry would know and the average layperson likely would not.”6 

Rather, the court opined, “[a] layperson could understand that a salon may be negligent in its training, supervision, and retention of a massage therapist who sexually assaults a disrobed customer in a private setting during a massage when the salon knew of the massage therapist’s prior inappropriate actions.”7

Readers contemplating whether the common knowledge-exception applies to a particular set of facts are urged to read this opinion to see how Tennessee courts have applied the principle over the years. The exception is not as broad as some have believed, as best evidenced by the dismissal of a fair number of cases after the plaintiff attempted to rely on the exception.

JOHN A. DAY is a plaintiff’s personal injury and wrongful death lawyer with offices in Nashville, Brentwood, and Murfreesboro. He recalls reading the “fly floating in a bowl of buttermilk” quote almost forty years ago and feels no small degree of pleasure at being able to work it into a title of a legal article. 



1. German v. Nichopoulos, 577 S.W.2d 197, 202–03 (Tenn. Ct. App. 1978), overruled on other grounds by Seavers v. Methodist Med. Ctr. of Oak Ridge, 9 S.W.3d 86 (Tenn. 1999).
2. These are the Latin words for the common green bottle fly.
3. 602 S.W.3d 340 (Tenn. 2020).
4. Id. at 350, citing Joseph H. King, “The Common Knowledge Exception to the Expert Testimony Requirement for Establishing the Standard of Care in Medical Malpractice,” 59 Ala. L. Rev. 51, 56 (2007)
5. Why is a case involving a massage a health care liability case? Because the owner of the day spa that employed the massage therapist is licensed and regulated under the Massage Licensure Act of 1995, Tenn. Code Ann.§§ 63-18-101 to -116, and thus is “health care provider” under Tenn. Code Ann. § 29-26-101(a)(2)(A) (2012) (a health care provider is “[a] health care practitioner licensed, authorized, certified, registered, or regulated under any chapter of [Tennessee Code Annotated] title 63 or title 68....)”
6. 602 S.W.3d at 350.
7. Id. The court then refused to dismiss the case for failure to file a certificate of good faith with the complaint (id.) correctly concluding that a certificate of good faith is not required in health care liability actions where expert testimony is not required by Tenn. Code Ann. § 29-26-115. Section 29-26-122 only requires a certificate of good faith in matters where expert testimony is required under § 29-26-115. Note that formal notice under Tenn. Code Ann. § 29-26-121 is still required in cases where the common knowledge exception applies; only the certificate of good faith-requirement is negated. title 68....).”