Plaintiffs Jaron and Rachel George (“Plaintiffs”) brought this subrogation action against Defendants Stanley Black & Decker, Inc. (“SBD”) and MTD Products, Inc. (“MTD”) for strict liability, negligence, and breach of warranty claims based on a riding lawnmower fire resulting in substantial damage to Plaintiffs’ home.
Defendants filed a motion in limine to exclude one of Plaintiff’s experts, Mr. Michael Zazula.
Zazula opined during discovery that Plaintiffs’ lawnmower was in a defective condition because it incorporated a muffler cannister that had become distended and bowed over the years, and a gap had been created between the muffler and deflector, raising temperatures in the engine that resulted in the fire.
Zazula did not point to any additional evidence of a defect at the time the lawnmower left the hands of Defendants but seems to suggest the distended muffler cannister itself was sufficient to prove a defect.
Mechanical Engineering Expert Witness
Michael J. Zazula specializes in applicable codes and standards for mechanical system components and the installation and maintenance of fire suppression systems, gas storage and delivery systems, boilers, HVAC equipment, and other fuel fired appliances.
With over 20 years of forensic experience, he has conducted over 2,000 investigations.
Discussion by the Court
Zazula’s testing regarding fire causation is not reliable
The basic premise of Zazula’s opinion is that the distention of the lawnmower’s muffler cannister was deformed, creating a 1/4 inch gap between it and the deflector, and this allowed hot exhaust gases to escape and caused higher temperatures and the ignition of combustible materials in the engine area.
He proffers that this condition was a design or manufacturing defect of the lawnmower. Defendants argued that the expert testimony Zazula offered to support this premise is not admissible pursuant to Daubert. This Court agreed that Zazula’s report and opinion should not be considered.
The methodology Zazula used for investigation and testing is Chapter 4 of the National Fire Protection Association (“NFPA”) 921, Guide for Fire and Explosion Investigations. The purpose of NFPA 921 “is to establish guidelines and recommendations for the safe and systemic investigation or analysis of fire and explosion incidents.”
Zazula’s report explained that he performed his testing on a “used” Cub Cadet LTX 1040 lawnmower like the subject 1045 tractor lawnmower, and both contained the same parts. The temperature testing, which used thermal probes, at various parts of the used lawnmower on or near the muffler indicated temperatures ranging anywhere from approximately 400 degrees to the high of 726 degrees. Significantly, however, Zazula admitted that he did not conduct any testing on a lawnmower without a “distended muffler” and a 1/4 inch gap to try to prove or disprove whether the gap did, in fact, increase the temperatures in the engine area.
Zazula could have fully tested his hypothesis, but he chose not to. Because he failed to conduct testing based on “the methods and procedures of science,” rather than mere “subjective belief,” the Court found that his opinion—that the muffler and the 1/4-inch gap (as a purported defect) caused the fire—was unreliable and inadmissible.
Zazula’s expert testimony regarding fire causation does not “fit” the case or assist the trier of fact
For similar reasons why Zazula’s opinion regarding the cause of the fire is not reliable, the Court held that Zazula’s opinion does not “fit” the case or assist the trier of fact. As explained before, it is not based on valid reasoning and reliable methodology. In addition, Zazula’s conclusion that the 1/4 inch gap caused the rise in temperatures is too speculative and subjective, considering he never conducted testing and compared temperatures in the engine of a lawnmower with a distended muffler and 1/4 inch gap and one without. This is especially so when two other experts who conducted the testing found no difference in the engine temperatures between the two.
Even assuming Zazula is qualified to opine about the cause of the fire in the lawnmower, for the reasons explained above, his opinion is unreliable and unhelpful to the jury and is therefore precluded based on Daubert.
Zazula is also not qualified as an expert to provide testimony regarding the alleged defective condition of the lawnmower, and the Court will exclude his opinion on that issue
Zazula proffered that the lawnmower at issue was defective because the distended muffler and the 1/4 inch gap suggested a manufacturing defect or design defect. When asked what evidence supported the existence of a manufacturing defect, Zazula pointed solely to the distended muffler and gap, stating if he took the muffler into MTD, MTD would say “that’s not right.”
Preliminarily, despite arguably being a fire causation expert, Zazula admitted he is not a design engineer regarding mufflers and exhaust systems, nor is he a warnings expert. Therefore, any of Zazula’s testimony regarding the lawnmower’s purported defects should not be considered. This includes his opinion without more that the distended muffler and 1/4 inch gap somehow was the result of the lawnmower’s defective condition, including a design defect, manufacturing defect, or failure to warn.
Even if Zazula was qualified to testify about the “defective condition” of the lawnmower, the Court held that his testimony is not reliable. While his report stated, in part, the muffler deformation and gap between the muffler and deflector “exacerbates the ignition of foreseeable combustible material . . . . when the hot exhaust are not properly vented out the side of the deflector as designed [and] intended,” during his deposition he gave no evidence to support or further explain any design defect theory.
The Court agreed that Zazula applied no methodology or procedures of science to support his opinion of a defect in the Cub Cabet at issue, and his opinion on any defect constitutes unreliable “subjective belief or unsupported speculation.”
Finally, and for similar reasons, the testimony is not helpful to the jury. Here, the testimony is not sufficiently tied to any of the facts to aid the jury in resolving whether MTD’s lawnmower, in fact, suffered from a defective condition.
Held
The Court granted Defendants’ motion in limine to exclude the testimony of Plaintiffs’ expert Michael Zazula.
Key Takeaway
Zazula speculates what possibly caused the fire (in a case where there are several possible fire causes), without providing any specific evidence or testimony to support his opinion that the lawnmower was defective. As a result, the Court determined that any of Zazula’s testimony about any defective condition of the lawnmower should be excluded.
Case Details:
| Case Caption: | George V. Stanley Black & Decker, Inc. |
| Docket Number: | 2:24cv2035 |
| Court Name: | United States District Court, Pennsylvania Eastern |
| Order Date: | January 26, 2026 |
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