Bruce Bunting fell as he exited a CVS location in the District of Columbia on the morning of December 24. The walkway was covered in a mix of salt or some de-icing material and water. Bunting suffered a significant ankle injury. He and his wife Jessie Brinkley sued District of Columbia CVS Pharmacy, LLC, in D.C. Superior Court, alleging negligence, negligence per se, and loss of consortium. CVS removed the case to federal court.
The central dispute was whether the walkway's static coefficient of friction fell below 0.50 — the standard of care both parties agreed applied. The Buntings retained Gregory Harrison, a registered professional civil engineer, who concluded the walkway was dangerously slippery when wet and that the COF was far below 0.50. CVS's own expert, Alexandra Maddox, a mechanical and biomedical engineer, produced field notes showing that a portion of the walkway near where Bunting fell had an average COF of 0.49 when wet. The district court nonetheless granted summary judgment to CVS, reasoning that Harrison had tested the surface with water alone rather than with the salt-and-water mixture present at the time of the fall.
The D.C. Circuit, in an opinion by Circuit Judge Rao, reversed on the negligence claim. The court agreed with the district court that expert testimony was required — coefficient of friction is a matter beyond an average juror's grasp — but held the district court erred in concluding that testimony was absent. Drawing all inferences in the Buntings' favor, the court held that a reasonable jury could conclude from both parties' expert evidence that the walkway's COF was below 0.50. The court further held that the inability to positively identify the salt-like substance, and the failure to test under combined salt-and-water conditions, did not foreclose a jury trial, because a reasonable jury could conclude the salt did not meaningfully mitigate the slippery surface.
The court affirmed summary judgment for CVS on the negligence per se claim. The Buntings argued that CVS violated D.C. Municipal Regulation section 2000.5, which prohibits leaving slippery substances on public space without protecting and guarding that space. The court held the regulation cannot support a negligence per se theory because it does not impose a duty distinct from the common law duty of reasonable care — both concern the protection of other persons from known hazards.
The court vacated the summary judgment in part and remanded. On remand, the district court must conduct its gatekeeping role under Federal Rule of Evidence 702 and assess the admissibility of the Buntings' expert testimony, and must also address CVS's alternative arguments, including whether CVS had actual or constructive notice of the hazard.
Circuit Judge Henderson concurred separately to flag serious reservations about Harrison's methodology. Harrison testified that he tested the walkway's COF using only a water bottle and a shoe, describing his approach as based on the surface's subjective feel, and said that after years of training and experience he had conditioned himself to become mentally calibrated to judge a surface's COF. He acknowledged he did not produce a precise numerical measurement and did not attempt to replicate the salt-and-water conditions Bunting described. Henderson wrote that Harrison's core finding bordered on ipse dixit and that his view that it is all the same because it is water hardly proved that replicating the alleged slurry conditions was unnecessary. She joined the opinion in full but emphasized these are issues for the district court to resolve under Rule 702.