The opinion of the court was delivered by: C. Clifford Shirley, Jr. United States Magistrate Judge
This case is before the undersigned pursuant to 28 U.S.C. § 636(b), the Rules of this Court, and by Order [Doc. 66] of the Honorable Thomas A. Varlan, United States District Judge, for disposition of Defendants' Motion in Limine to Exclude the Testimony of Plaintiff's Proposed Expert, Dr. Charles Benedict [Doc. 44] pursuant to Rule 702 of the Federal Rules of Evidence and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). The undersigned conducted a Daubert hearing on July 10, 2006. Dr. Benedict was present as the only witness at the Daubert hearing.
The plaintiff Robert Alan Christie, II ("Christie") brings this action against the defendants Mazda Motor of America, Inc. and Mazda Motor Corporation (collectively "Mazda") for damages arising from injuries he sustained in a collision with another vehicle on July 31, 2002.
Christie alleges that the 1995 Mazda Miata he was driving was defective in that its "occupant protection system, supplemental restraint system and seat system were in a defective or unreasonably dangerous condition . . . ." [Complaint ¶ 10].
Christie has retained Dr. Charles Benedict as a trial expert regarding alleged defects in the vehicle. Dr. Benedict is a licensed professional engineer, who has extensive experience in vehicle accident reconstruction, product design, and failure analysis, including vehicle restraint systems. [Benedict Aff. ¶¶ 3-8]. He is the president and majority shareholder of Benedict Engineering Company. [Benedict Dep. at 6-7].
In his first report dated February 26, 2004, Dr. Benedict stated the following opinions: (1) the structural integrity of the hood is inherently defective and unreasonably dangerous because it penetrated the windshield in violation of Federal Motor Vehicle Safety Standards ("FMVSS") 219; (2) the airbag is inherently defective and unreasonably dangerous in that it failed to protect Christie from the severe forces applied to his head as a result of impact; and (3) the restraint system is inherently defective and unreasonably dangerous in that it failed to properly restrain Christie and prevent him from striking his head on the interior components of the vehicle. With respect to this last opinion, Dr. Benedict specifically opined that the restraint system is defective and unreasonably dangerous because the seat buckle inertially unlatched during the collision. [Doc. 44 Ex. 2].
On November 15, 2005, Dr. Benedict submitted a supplemental report based on additional information regarding the condition of the restraint system at the time that EMT personnel removed Christie from the vehicle. Specifically, Carver Lovely, one of the EMT personnel on site who assisted in removing Christie from the vehicle, testified that there was a seat belt restraining Christie, but that he could not remember whether the belt buckle was still latched or if the belt was just hooked around Christie's clothing. Based upon these additional details, as well as additional testing that Dr. Benedict performed, Dr. Benedict additionally opined that the seat belt retractor failed to lock in accordance with FMVSS 209 and spooled out approximately 22 inches, allowing Christie to strike the top of the windshield header with his eyes. Dr. Benedict opines that the retractor's design is inherently defective and unreasonably dangerous because the retractor will not lock up consistently. He further opines that this spooling-out is conducive to and consistent with inertial unlatching of the buckle because it reduces tension in the webbing and subsequently lowers the forces acting between the latch plate and the buckle. Dr. Benedict states that either the spooling-out or inertial unlatching alone could have caused Christie to become unrestrained, but that it is also likely that both conditions could have occurred and that these defects acting in combination with one another would have also caused Christie to become unrestrained. [Doc. 44 Ex. 3].
II. APPLICABLE LAW: ADMISSIBILITY OF EXPERT TESTIMONY
Mazda challenges Dr. Benedict's opinions under Rule 702 of the Federal Rules of Evidence and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).*fn1 Rule 702 of the Federal Rules of Evidence governs the admissibility of expert testimony:
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.
The trial judge must act as a gatekeeper, admitting only that expert testimony that is relevant and reliable. Daubert, 509 U.S. at 589. With regard to scientific knowledge, the trial court must initially determine whether the reasoning or methodology used is scientifically valid and is properly applied to the facts at issue in the trial. Id. at 590. To aid the trial court in this gatekeeping role, the Supreme Court has listed several key considerations: (1) whether the scientific knowledge can or has been tested; (2) whether the given theory or technique has been published or been the subject of peer review; (3) whether a known error rate exists; and (4) whether the theory enjoys general acceptance in the particular field. Id. at 592-94. The Court's focus "must be solely on principles and methodology, not on the conclusions that they generate." Id. at 595. "[T]he test under Daubert is not the correctness of the expert's conclusions but the soundness of his methodology." Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311, 1318 (9th Cir. 1995).
Although Daubert centered around the admissibility of scientific expert opinions, the trial court's gatekeeping function applies to all expert testimony, including that based upon specialized or technical, as opposed to scientific, knowledge. Kumho Tire Co. v. Carmichael, 526 U.S. 137, 147-48 (1999); Berry v. City of Detroit, 25 F.3d 1342, 1350 (6th Cir. 1994). The trial court's objective "is to make certain that an expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field." Kumho Tire, 526 U.S. at 152. The trial judge enjoys broad discretion in determining whether the factors listed in Daubert reasonably measure reliability in a given case. Id. at 153. With this framework in mind, the Court will now address Mazda's motion.
Mazda contends that Dr. Benedict's proposed testimony will not assist the trier of fact to determine a fact in issue because Dr. Benedict admitted in his deposition that he could not determine whether Christie's injuries were caused by seat belt spool-out or by intertial unlatching of the buckle or by both. Mazda further argues that Dr. Benedict's proposed testimony and conclusions are fundamentally flawed because they are not based on principles of the scientific method. Specifically, Mazda claims that Dr. Benedict's methodology does not support his conclusion that the seat belt buckle inertially unlatched, as Dr. Benedict has provided no mathematical calculations that can be reproduced to establish that sufficient vertical G-forces were imparted on the seat belt buckle to cause inertial unlatching. Further, Mazda claims that Dr. Benedict's methodology does not support his conclusion that spool-out of the seat belt webbing caused plaintiff's injuries because Dr. Benedict failed to use any scientific methodology to establish how much spool-out actually took place. Finally, Mazda claims that Dr. Benedict's conclusions regarding the hood and the airbag are not supported by any evidence in this case. [Docs. 45, 67].
Christie opposes Mazda's motion, arguing that Dr. Benedict's opinions are grounded in fact and in the proper application of recognized and accepted scientific methodology. Accordingly, Christie argues, Dr. Benedict's testimony should be admitted and that the weight to be given his opinions should be determined by the jury. [Doc. 64].
Mazda argues that Dr. Benedict's proposed testimony will not assist the trier of fact to determine a fact in issue. Specifically, Mazda argues that Dr. Benedict admitted in his deposition that he could not determine whether Christie's injuries were caused by seat belt spool-out or by inertial unlatching of the seat belt buckle:
Q: Do you believe -- which one do you believe happened in this accident or do you believe both happened in this accident?
A: Let me put it this way. If [the seat belt] was hooked up still, then it just spooled out. If it was retracted and off of him, or loose, as Mr. Lovely might have supposed in his testimony, then it became unlatched.
But in terms of the spool out and what have you, he has to spool out or unlatch to allow him to go forward. But if it unlatches and it's still on him, then it still had to spool out on top of it; otherwise it would have jerked it off of him -- it, the latch plate and everything -- and it would have retracted himself.
So there is no way to tell one way or the other whether one or both of them, either one or both of them happened.
Q: But you are certain that at least one or both of those occurred, spool out and inertial release?
A: Either one or both of them, yes. [Benedict Dep. at 91-92]. Mazda contends that this deposition testimony illustrates that Dr. Benedict cannot determine the defect that allegedly caused Christie's injuries, and therefore, his testimony will not assist the trier of fact to determine a fact in issue.
In response to this argument, Christie argues that Daubert does not require an expert to eliminate all causes of the alleged injury, nor does it require absolute certainty of result or unanimity of scientific opinion before an expert's opinion is admissible. [Doc. 64].
The Court agrees with Christie that Dr. Benedict's opinions are not rendered inadmissible simply because he does not eliminate all possible causes of Christie's injuries. "The fact that several possible causes might remain 'uneliminated' . . . only goes to the accuracy of the conclusion, not to the soundness of the methodology." Jahn v. Equine Services, PSC, 233 F.3d 382, 390 (6th Cir 2000) (quoting Ambrosini v. Labarraque, 101 F.3d 129, 140 (D.C. Cir. 1996)). In his deposition, Dr. Benedict poses three alternative theories of causation with regard to the failure of the seat belt restraint system: he states that Christie's injuries were caused by either inertial unlatching, seat belt spool-out, or a combination of these two occurrences.
The need for these alternative theories arises because one of the most significant factual disputes in the case is whether Christie was in fact wearing a seat belt at the time of the collision. Mazda claims that Christie was not restrained prior to this collision. Christie, on the other hand, claims that he was restrained prior to the accident but became unrestrained during the accident.
Dr. Benedict explained in his deposition that he excluded the possibility that Christie was not wearing a seat belt because there was "evidence that the thing did spool out some because there is some burn evidence on the D-ring and latch plate." [Benedict Dep. at 92]. Mazda, of course, disputes this evidence, and it is far from a forgone conclusion that Christie was belted prior to the accident. It appears, at least from the opinions offered by Dr. Benedict, that Christie suffered injuries that are indicative of an unrestrained occupant. Whether these injuries occurred because Christie was not wearing a seat belt at the time of the collision or because he was wearing a seat belt but the seat belt failed is ultimately an issue for the jury in this case.
Even assuming that the seat belt was in use prior to the collision, the factual evidence as to whether the seat belt was still engaged at the time that the EMT personnel removed Christie from the car is unclear. EMT Lovely testified that he believed there was a seat belt restraining Christie, but that he could not remember whether the belt buckle was still latched or if the belt was just hooked around Christie's clothing, nor could he remember whether the release button on the buckle had to be pushed in order to free Christie from the belt in order to remove him from the vehicle. In light of this testimony, Dr. Benedict testified as follows:
A. When we first looked at it, it was my opinion based on the fact that he was wearing the belt and there is evidence that it spooled out some on the D-ring and on the latch plate itself; it was my initial opinion, given all of that, that it came inertially unlatched because it will inertially unlatch in an accident of this type. That's number one. But considering the fact that Mr. Lovely says it was still connected, then if that is the case, and nobody really knows, not even him -- it's his belief based upon what he can recollect that certain things were certain ways -- but if it was still connected, then it had to spool out. That is all.
And it could be either one or the other or both. That's why what I said in the supplemental report about it could be one or the other or both, because they both can happen. [Benedict Dep. at 90-91].
Given Lovely's testimony (as well as other evidence in the record), a classic jury question is presented as to whether Christie was wearing a seat belt and, if so, whether the seat belt was still latched after the collision. The mere fact that such factual disputes exist, however, does not render Dr. Benedict's alternative causation theories inadmissible as unhelpful to the trier of fact. Indeed, as Dr. Benedict explains in his supplemental report, it is his opinion that inertial unlatching or spool-out (or a combination of these two conditions) could have occurred in this ...