United States Court of Appeals For the Seventh Circuit ____________________ No. 22-2610 NATALIE JOHNSON, Plaintiff-Appellee, v. C. R. BARD, INC., and BARD PERIPHERAL VASCULAR, INC., Defendants-Appellants. ____________________

Appeal from the United States District Court for the Western District of Wisconsin. No. 19-cv-760-wmc — William M. Conley, Judge. ____________________

ARGUED JUNE 1, 2023 — DECIDED AUGUST 11, 2023 ____________________

Before EASTERBROOK, WOOD, and PRYOR, Circuit Judges. WOOD, Circuit Judge. Hoping to minimize her risk of suf- fering serious complications from future blood clots, plaintiff Natalie Johnson underwent surgery to implant a retrievable intravascular filter. Intravascular filters are medical devices that are placed in the inferior vena cava (the major lower vein that carries blood to the heart) to prevent blood clots that de- velop in the lower body from flowing into the heart and lungs. Johnson’s doctor selected the Meridian filter, which was 2 No. 22-2610 supposed to be temporary and easily removeable. It was not. Instead, Johnson’s filter migrated and fractured, leaving shards embedded in the wall of her heart and elsewhere. Her surgeon was unable to remove the device safely and fully. She now faces an ongoing risk of infection, pain, and other com- plications as a result of the broken filter. Johnson sued the manufacturers of the Meridian filter— C.R. Bard, Inc., and Bard Peripheral, Inc. (together, “Bard”)— claiming that they defectively designed the Meridian filter and failed to warn medical providers about the device’s risks, in violation of Wisconsin law. A jury cleared Bard on most of Johnson’s theories, but it returned a $3.3 million verdict in her favor on her strict liability failure-to-warn count. Bard moved for a new trial on a host of issues, but the district court denied the motion. We affirm. I Johnson’s case is one of several that were remanded for further proceedings following the conclusion of multidistrict litigation related to alleged defects in Bard’s intravascular fil- ters. See In re Bard IVC Filters Prod. Liab. Litig., No. MDL 15- 02641, 2019 WL 3928657 (D. Ariz. Aug. 20, 2019). At trial, she argued that Bard was liable for her injuries under several Wis- consin-law theories: negligent defective-design, strict liability defective-design, negligent failure-to-warn, and strict liability failure-to-warn. Johnson’s main contention was that Bard’s Meridian filter was defectively designed because it had an un- acceptably high risk of migration or fracture, or both, and that Bard failed properly to warn users about these risks. Bard’s central defense (as relevant to this appeal) was that Johnson’s problems came about because her surgeon, Dr. Irina Goncha- rova, had placed the filter too high (i.e. toward the heart) in No. 22-2610 3 the wall of the vein. Bard contended that Johnson’s injuries were caused by that improper placement, not any problem with the device. Among Johnson’s witnesses was Dr. Darren Hurst, a vas- cular and interventional radiologist. In his expert report and deposition testimony, Hurst stated that CT scans taken a few days after Goncharova implanted Johnson’s filter showed that the filter had migrated down by 3 millimeters. At trial, however, he testified that the scans showed that the filter had migrated upward by 2.5 or 2.3 centimeters. This led Bard to ob- ject at various times on nondisclosure grounds, an issue that we discuss in more depth in Part II.A, infra. Johnson also called Goncharova to testify, but securing her appearance turned ou