LEONARD T. STRAND, Magistrate Judge.
This case is before me on two motions filed by the defendant: (a) a motion to exclude the opinions of plaintiffs' liability expert (Doc. No. 21) and (b) a motion for summary judgment (Doc. No. 22). Both motions are resisted and have been thoroughly briefed. I heard oral arguments on July 24, 2013. David Taylor appeared for the plaintiffs and Kevin Reynolds appeared for the defendant. The motions are fully submitted.
Plaintiffs Jason Martin and Amber Martin filed this action in the Iowa District Court for Cerro Gordo County on February 2, 2012. In their petition, they allege that defendant Apex Tool Group, LLC (Apex), manufactures, distributes and sells the GearWrench brand of pry bars. They further allege that Martin purchased a GearWrench pry bar from a NAPA Auto Store in Mason City, Iowa, on August 27, 2008, and that the product included a lifetime warranty. They contend that on February 5, 2010, while Martin was working at an auto repair facility, the pry bar failed when being used in a reasonably-foreseeable manner, causing personal injuries to Martin. They also contend that the NAPA Auto Store replaced the failed pry bar on February 9, 2010, pursuant to the terms of the lifetime warranty. Their petition states claims for strict liability, negligence and breach of warranty and alleges that the pry bar at issue suffered from manufacturing defects and design defects.
Apex removed the case to this court on March 15, 2012, invoking the court's diversity jurisdiction pursuant to 28 U.S.C. § 1332. Apex later filed an answer in which it denies liability and asserts various affirmative defenses including comparative fault, the impact of certain alleged contractual provisions and a state of the art defense.
The parties then consented to trial, disposition and judgment by a United States Magistrate Judge pursuant to 28 U.S.C. § 636(c). The case was assigned to me by order (Doc. No. 7) entered June 18, 2012. Trial is set to begin October 21, 2013. On June 3, 2013, Apex filed its two pending motions. In its motion to exclude the opinions of plaintiffs' liability expert, Apex challenges the admissibility of certain opinions, especially a causation opinion, reached in this case by James Brusso, Ph.D. In its summary judgment motion, Apex contends that if Dr. Brusso's opinions are excluded, then entry of summary judgment necessarily must follow because plaintiffs cannot present a viable case at trial without expert testimony.
These facts are not in dispute for purposes of Apex's pending motions:
The Pry Bar. As noted above, Martin purchased the pry bar in August 2008. The bar was both extendable and indexible. That means the handle could be adjusted for length and its pry tip (the pointed, working end of the tool) could be rotated to various angles with respect to that handle. The extendable handle was connected to the pry tip by an indexing gear.
The Accident. Martin testified that on February 5, 2010, he was working as a mechanic at Complete Auto Repair in Mason City. While performing work on a 1992 Plymouth Acclaim, he used the pry bar to remove the lower ball joint out of the steering knuckle. He was using his left arm to apply his body weight to the bar. The bar was fully extended. He states that the pry tip was in line with the pry bar handle and the direction of the force Martin was applying. In other words, according to Martin, he was not applying force in a perpendicular, or sideways, manner in relation to the direction of the pry tip. Martin testified that he knew he should not apply force in that manner. The pry bar snapped while Martin was applying force with his left arm. This caused him to fall and he incurred injuries to his left arm.
The Return. On February 9, 2010, the NAPA Auto Store in Mason City, Iowa, replaced the failed pry bar pursuant to a lifetime warranty. The return form indicates the NAPA employee found that the bar "failed integrity test." Apex reimbursed the NAPA store for the replacement bar.
Dr. Brusso's Opinions. Plaintiffs retained Dr. Brusso to evaluate the pry bar, determine its failure mode and provide an opinion concerning the root cause of its failure. He issued a report dated November 30, 2012 (filed herein as Doc. No. 21-2). His report describes various analyses, including a visual examination, hardness testing, chemical analysis, scanning electron microscopy and a metallographic examination. After some discussion of the results, Dr. Brusso stated the following opinions:
1. The failed hex extension bar is manufactured using AISI 6150 steel.
2. The failed hex bar has been heat treated to a high strength level by quenching and tempering. The hardness of the pry bar, 48.2 HRC, indicates an approximate tensile strength of 238, 000 psi.
3. The hardness of the pry bar, although near the upper limit, meets the 50 HRC maximum hardness specified for pry bars in ASME B107.60-2004.
4. A pre-existing crack/defect was present in the hex extension bar prior to final heat treatment and assembly. Based on the results of this evaluation, this manufacturing defect is the cause of the present failure.
5. Design information for the pry bar was not available for review at the time of this report. Therefore, the adequacy of the design of the failed extendable, indexible pry bar could not be determined. Inadequate design could not be eliminated as a contributing cause of the failure.
6. The failed pry bar exhibits normal wear for a shop hand tool. There is no evidence of mechanical damage to the pry bar from mis-use or abuse. Therefore, mis-use and ...