## Facts

- Supreme Pork, Inc. operated a pig farrowing facility near Lake Benton, Minnesota.
- After a 1999 fire in the pressure-washer room, Supreme Pork hired Master Blaster, Inc. to add and install a second power washer; the venting system was to be redesigned and a new chimney installed.
- Master Blaster did not perform the venting/chimney work itself; it recommended Pipestone Plumbing & Heating (PP&H), contacted PP&H, obtained its quote, and billed Supreme Pork for PP&H’s quoted price plus an added fee.
- On March 21, 2002, a second fire started above the pressure-washer room ceiling near the exhaust chimney, causing major damage.
- Supreme Pork sued Master Blaster, alleging PP&H negligently installed the chimney/venting and that Master Blaster was vicariously liable for PP&H’s negligence.
- The trial court applied Minnesota law, found PP&H acted as Master Blaster’s subcontractor/agent for the project, and treated Master Blaster as liable for PP&H’s negligent work.
- At the 2007 jury trial, the court admitted expert and contextual evidence including non-causal code violations, a manufacturer recommendation for a more insulated chimney, testimony about an expert’s post-deposition work, evidence of a prior 1999 fire connected to PP&H’s installation, and expert testimony that “pyrolysis” explained ignition.
- The jury found Master Blaster liable for Supreme Pork’s fire damages; Master Blaster appealed.

## Issues

1. Whether the trial court erred by not giving additional jury instructions on agency and independent-contractor status regarding PP&H.
2. Whether the trial court abused its discretion by admitting evidence of non-causal building code violations, a prior 1999 fire linked to PP&H’s work, a manufacturer’s chimney insulation recommendation, and an expert’s post-deposition preparation.
3. Whether the trial court abused its discretion by admitting expert scientific testimony on “pyrolysis” as a fire-causation mechanism under reliability standards for scientific evidence.

## Decision

- The Supreme Court of South Dakota affirmed the judgment for Supreme Pork.
- The court held that the absence of additional agency/independent-contractor instructions was not reversible error because the relevant relationship and vicarious-liability framework had been determined by the court as a matter of law under Minnesota law.
- The court held the challenged evidence was within the trial court’s discretion to admit and was used for permissible purposes such as knowledge and foreseeability, not propensity.
- The court held the “pyrolysis” testimony satisfied reliability and relevance requirements for expert scientific evidence and was properly submitted to the jury on causation.
- The court concluded that any arguable evidentiary errors did not amount to prejudicial error warranting reversal.

## Legal Principles

- When governing law makes a contractor responsible for a subcontractor’s negligent performance, the trial court may treat the relationship and resulting vicarious-liability consequence as a legal determination rather than a jury question.
- Evidence of non-causal code violations and prior similar incidents may be admissible for non-propensity purposes, including knowledge, foreseeability, and context, subject to the trial court’s discretion.
- Expert testimony on a scientific mechanism of causation is admissible when it is supported by scientific research/methodology and is relevant to disputed issues; the trial court’s reliability ruling is reviewed for abuse of discretion.
- Appellate relief based on evidentiary rulings generally requires a showing of prejudice affecting the verdict.

## Conclusion

The court upheld a jury verdict imposing liability on a contractor for fire damages tied to a subcontractor’s chimney/venting work, and it affirmed the trial court’s discretionary evidentiary rulings, including admission of background evidence bearing on knowledge and foreseeability and expert testimony that pyrolysis explained the ignition mechanism.


Supreme Pork, Inc. v. Master Blaster, Inc., 764 N.W.2d 474 (S.D. 2009)