## Facts

- Jennifer Jones worked as a press operator for Business Cards Tomorrow (BCT) and was injured while operating an offset duplicator used to print and eject sheets through moving “eject wheels.”
- The operator routinely adjusted eject wheels to avoid streaking freshly printed images.
- When manufactured and sold, the press included (1) a plastic guard preventing access to moving parts during adjustment and (2) an interlock switch shutting the press off if the guard was opened.
- After delivery, BCT (or another third party) removed the guard and disabled the interlock switch so the press could run with the guard off; the change was described as common in the industry because it saved time.
- Jones learned by observing coworkers, knew the guard was missing, and understood the danger of placing hands near exposed moving parts.
- Jones testified she felt pressured to adjust the wheels while the press was running to save time.
- While adjusting the wheels with the press running, Jones was startled by a noise; her hand was caught in the moving parts, causing serious injury.
- Jones sued the manufacturer (Ryobi) and distributor (A.B. Dick) in diversity, initially pleading negligence and strict products liability for defective design; she later proceeded only on strict liability, then sought late amendment to reassert negligence against the distributor.
- The district court granted judgment as a matter of law for both defendants at the close of Jones’s case; Jones appealed.

## Issues

1. Whether a manufacturer and distributor may be held strictly liable for defective design when the injury occurs after a third party substantially modifies the product by removing safety devices.
2. Whether the plaintiff presented sufficient evidence that the product was defective when sold and that any defect in that original condition caused the injury.
3. Whether the district court abused its discretion in denying a late motion to amend to reassert negligence against the distributor.

## Decision

- The Eighth Circuit affirmed judgment as a matter of law for both defendants.
- The court held Jones failed to prove the press was defective when sold or that any design defect in its original condition caused her injury.
- The court concluded the third-party removal of the guard and disabling of the interlock switch created the dangerous condition and severed strict-liability causation, even if such modification was foreseeable.
- The court held the district court acted within its discretion in denying the late motion to amend to reassert negligence against the distributor.

## Legal Principles

- In a strict products-liability design-defect claim under Missouri law, the plaintiff must prove the product was defective when it left the seller’s control and that the defect directly caused the injury.
- A manufacturer or seller is not strictly liable when a third party’s post-sale modification renders a product unsafe and causes the injury, including where the modification is foreseeable.
- Judgment as a matter of law is proper when the plaintiff’s evidence cannot support a finding that the unmodified product was unreasonably dangerous or that an at-sale defect caused the injury.
- Leave to amend may be denied when sought late after a case has been tried on a different theory and the proposed claim would be unsupported or futile.

## Conclusion

The court affirmed dismissal because the injury resulted from an employer’s disabling of the press’s safety features, and the plaintiff did not produce evidence that the product was defectively designed or causally unsafe in its original condition at the time of sale; the court also upheld denial of a late amendment to add negligence.


Jones v. Ryobi, Ltd., 37 F.3d 423 (8th Cir. 1994)