## Facts

- Ronnie Davis, a minor, was killed when the automobile in which he was a passenger crashed after an alleged tire “blowout.”
- The tire involved was a Dayton 9-70 Sport Tire manufactured by Dayton Tire and Rubber Company.
- The tire had been purchased from John Mott’s Sunoco Service, Inc., and installed on the vehicle by an employee of Mott’s.
- At the time of the accident, the tire was about six months old and had been driven approximately 4,000 miles.
- The plaintiff (Clyde E. Davis, individually and as administrator of Ronnie’s estate) brought a wrongful-death action alleging negligence by:
  - Dayton in manufacturing and inspection (including use of defective materials) and in failing to warn; and
  - Mott’s, as retail seller/installer, in failing to inspect, warn, and instruct regarding use.

- Evidence was presented both supporting and disputing that the tire was defective and whether any manufacturing-related condition caused the blowout; the cause of the failure was contested.
- The jury returned a verdict against Dayton and in favor of Mott’s; the trial court entered judgment on the verdict.
- Dayton appealed, arguing the trial court improperly instructed the jury on res ipsa loquitur.
- Davis cross-appealed as to Mott’s, relying in part on testimony about a cut/rupture in the valve-stem area and challenging the trial court’s denial of a motion to amend the pleadings during trial to conform to that evidence.

## Issues

1. Whether the trial court erred by instructing the jury on res ipsa loquitur against the manufacturer in a tire-blowout case where the tire had been in use for months and the proof included competing explanations for the failure.
2. Whether the judgment for the retail seller/installer should be reversed based on the evidence presented and the trial court’s denial of the plaintiff’s mid-trial motion to amend the pleadings to add or shift theories involving the valve-stem condition.

## Decision

- The judgment against Dayton was reversed and the cause was remanded for a new trial because the res ipsa loquitur instruction was improper on this record.
- The judgment in favor of John Mott’s Sunoco Service, Inc. was affirmed.
- The appellate court found no reversible error in the trial court’s handling of the plaintiff’s attempt to rely on valve-stem testimony and no abuse of discretion in denying the requested amendment of the pleadings.

## Legal Principles

- Res ipsa loquitur permits, but does not require, an inference of negligence only when the occurrence is of a kind that ordinarily does not happen without negligence and the circumstances reasonably connect the event to the defendant’s negligence.
- In product-defect cases, use of res ipsa loquitur generally requires a showing that the product was not materially changed, mishandled, or subjected to other forces after leaving the defendant’s control such that alternative causes are reasonably excluded.
- A res ipsa loquitur instruction is improper where the evidence and circumstances allow multiple reasonable explanations for the failure and the plaintiff has not supplied a basis to treat the accident itself as speaking to negligence by the manufacturer.
- A retailer’s negligence based on failure to inspect or warn requires evidence that the alleged defect was discoverable by reasonable inspection at the retail level; where the proof shows the defect was not discoverable, liability may not be imposed on a negligence theory.
- Trial courts have broad discretion to allow or deny amendments to pleadings during trial; denial is not reversible absent an abuse of discretion, especially when the proposed change would introduce a new or speculative theory late in the case.

## Conclusion

The court ordered a new trial as to the manufacturer because the res ipsa loquitur instruction improperly allowed the jury to infer negligence from the blowout despite contested proof and plausible non-manufacturing causes after months of use, but it left intact the defense judgment for the retailer because the plaintiff did not present evidence that any defect was discoverable by the retailer and the trial court acted within its discretion in refusing a late amendment tied to valve-stem testimony.


Dayton Tire and Rubber Company v. Davis, 384 So. 2d 575 (1977)