Opinion ID: 894934
Heading Depth: 2
Heading Rank: 1

Heading: Admissibility of Ledesma's Expert Testimony

Text: Ford argues that the trial court erred in admitting the testimony of Ledesma's two expert witnesses because their opinions were unreliable. [2]
Ledesma's expert David Hall, an accident reconstructionist, testified by deposition that he believed a mark in the road showed that the drive axle struck the pavement before the truck struck the Firebird, consistent with Ledesma's theory that the truck malfunctioned and caused the collision. He reached this conclusion by reviewing a number of photographs. Based on the photographic evidence of damage to the Firebird and an engineering paper providing a method for estimating speed based on the Firebird's body damage, Hall also estimated that Ledesma's truck was traveling at a very slow speed when it struck the Firebird, again consistent with Ledesma's theory of the accident and inconsistent with Ford's theory that Ledesma was speeding and otherwise driving carelessly. Ford raises numerous complaints about the reliability of Hall's testimony. Ford notes that the post-accident photographs of the road were taken by Ledesma and his father with a low-quality disposable camera, that there are many spots and marks on the grainy photographs, and that the marks do not reliably indicate that the drive shaft struck the road prier to the crash with the Firebird. Ford stresses that the investigating police officer found no gouges in the pavement despite a careful search of the accident scene. Ford also raises numerous complaints about Hall's estimate of the truck's speed at the time of the Firebird collision. These complaints include two observations: (1) the engineering paper on which Hall relied states that it should not be used when examining side swipes such as the accident in issue; and (2) the damage to the Firebird, as confirmed by the car's owner and a repair estimate, was far more severe than Hall assumed, rendering his estimate of a very slow impact unreliable. Ford complains that the testimony of Ledesma's principal expert, metallurgical and mechanical engineer Geert Aerts, was likewise unreliable. Ledesma counters that Aerts is a leading expert on truck leaf springs; Aerts has investigated about 150 leaf-spring failures. Ford does not claim that Aerts was unqualified to testify as an expert on the accident in issue but contends that his theory of the accident was unreliable for various reasons. Aerts focused on the u-bolts holding the rear axle to the rear springs and concluded that one of them was defectively manufactured. His theory was that a rear passenger-side u-bolt was loose, causing it to vibrate. This vibration eventually fatigued and fractured a center pin holding the leaf springs to the rear spring plate, which in turn allowed the u-bolts, spring plate, and rear axle to slide backwards, pulling the drive shaft from the transmission. Aerts examined the truck's u-bolts while they were still on the truck and found the torque on each bolt to be well below that required by Ford's specifications. While he conceded that the torques might have changed due to the accident, he concluded that the u-bolt in issue was under-torqued when Ford assembled the truck. Aerts testified extensively about how the th:bolt came to be under-torqued. One explanation was that one leg of the u-bolt was manufactured a few millimeters higher than the other, which could have caused the nut on the shorter leg to receive an insufficient torque when it and other nuts were simultaneously tightened. Aerts claimed that, according to a Ford product engineering sheet for the u-bolt, admitted into evidence, this slight difference in heights of the legs exceeded the tolerance in Ford's own specifications. The engineering sheet provided diagrams and various specifications for the u-bolts. Aerts also testified that the product en gineering sheet required the bottom, curved portion of the u-bolt to be flattened to allow for a better grip on the axle, and that the flattened portion on the allegedly defective bolt was off center by about three-quarters of an inch. According to Aerts, this manufacturing defect reduced the surface area of the bolt in contact with the axle, thus reducing the bolt's grip on the axle. This defect also allegedly allowed the bolt to dig into and deform the axle housing, causing the bolt to further loosen over time. The product engineering sheet clearly shows that the flattened portion of the u-bolt is to be centered at the bottom of the curved portion of the bolt, with flattening forty-five degrees up from either side of the bottom of the bolt, and a blend from flat to round for another forty-five degrees on both sides of the bolt. As further evidence of a pre-accident defect, Aerts focused on the rear spring plate. The u-bolts went through this plate, which sits on top of the leaf springs. The u-bolts were tightened onto the plate with four nuts. The rear spring plate also had a center pin attaching the leaf springs to the plate. Aerts claimed that rust and marks on the spring plate near the hole for the center pin indicated that the u-bolt was loose, allowing the assembly to vibrate and the pin to, scratch the spring plate over a period of time. These observations were consistent with his theory of a u-bolt that was loose before the accident, resulting in vibration that caused the center pin to suffer a fatigue fracture and precipitate the u-bolt slippage and drive shaft dislocation. Aerts also theorized that, perhaps for a reason other than the uneven u-bolt ends and flattened portion of the bolt, Ford simply failed to tighten the u-bolts to the torque required by its own specifications, causing the assembly to vibrate and eventually fail after a few months of driving. Ford challenged Aerts's testimony at every turn. It argued that Aerts never confirmed the existence of denting in the axle housing and that Ford's expert May testified that he could find no such denting. Ford contended that the u-bolt was deformed because of the tremendous forces of the accident. It further offered evidence from May, who was familiar with Ford's manufacturing process, that the sockets on its four spindle nut runner, the machine used to tighten the nuts onto the u-bqlts, are four inches deep, easily deep enough to properly tighten the nuts despite the slight difference in the height of the u-bolt legs. May claimed that the difference in the u-bolt lengths was within Ford's allowable tolerances. May also testified that he could not see the .75-inch misalignment of the flattened portion of the u-bolt that Aerts observed.
An expert's testimony, to be admissible, must possess a reliable foundation. [3] Admission of expert testimony that does not meet the reliability requirement is an abuse of discretion. [4] Expert testimony is unreliable if it is based on unreliable data, or if the expert draws conclusions from his underlying data based on flawed methodology. [5] Expert testimony is also unreliable if there is simply too great an analytical gap between the data and the opinion proffered. [6] In E.I. du Pont de Nemours & Co. v. Robinson, 923 S.W.2d 549 (Tex.1995) we set out six factors courts may consider in deciding whether expert testimony is reliable: 1. the extent to which the theory has been or can be tested; 2 the extent to which the technique relies on the subjective interpretation of the expert; 3. whether the theory has been subjected to peer review and/or publication; 4 the technique's potential rate of error; 5. whether the underlying theory, or technique generally has been accepted as valid by the relevant scientific community; and 6 the nonjudicial uses which have been made of the theory or technique. [7] We have recognized that the Robinson factors are nonexclusive [8] and have specifically noted that the Robinson factors are not always useful in evaluating expert testimony in automobile accident cases. [9] As in Gammill v. Jack Williams Chevrolet, Inc ., another automobile accident case, the Robinson factors do not readily lend themselves to a review of the expert testimony in the pending case, [10] but there must be some basis for the opinion offered to show its reliability. [11] And as in Volkswagen of America, Inc. v. Ramirez, yet another automobile accident case, [a]n expert's bare opinion will not suffice and is unreliable if based solely upon his subjective interpretation of the facts. [12] We need not assess the reliability of Hall's testimony, because we hold that Aerts's testimony was sufficiently reliable to warrant admission and is some evidence that a manufacturing defect caused the accident. Ford never challenged Aerts's credentials. His testimony offered, a plausible theory of how the accident occurred. Aerts based his testimony on deviations between Ford's own specifications as to torque, alignment of the flattened portion of the u-bolt, and the tolerance for the difference in u-bolt leg lengths. He relied on observations and measurements of tangible truck components, which were documented with photographs and a videotape of his initial examination of the truck. The u-bolts and rear-axle assembly were admitted into evidence. The jury was free to examine this, evidence and the Ford specifications that were also admitted into evidence. To a significant extent, deciding whether the truck lost its drive shaft before striking the Firebird, or instead the drive shaft dislodged after striking the parked cars and the street curb, turned on whether the jury believed Ledesma or Plyant. Ledesma insisted he was driving carefully when suddenly he lost control of the truck and veered into the Firebird. He claims that the truck started lurching before the impact, consistent with a truck malfunction that caused the drive shaft to drop to the street. Pylant's testimony was inconsistent with the investigating police officer's report and testimony, which indicated that Plyant talked to the officer but did not claim to have, witnessed the accident. Ledesma likewise observed no witnesses to the accident, claiming instead that Plyant and others came outside after hearing the accident. The jury was of course entitled to weigh the credibility of these lay witnesses and apparently believed Ledesma's account. The jury was also entitled to take into account that Ford's expert May had worked for Ford for decades and had never found a defect in a Ford product. We also conclude that Ford overstates the effectiveness of its cross-examination of Aerts. While May explained that Ford's tightening equipment provided sockets easily deep enough to tighten the uneven legs of the u-bolt, Aerts claimed that the uneven legs might still cause the equipment to slip off the shorter leg, or under-tighten the shorter leg if the equipment lacked the flexibility to properly tighten uneven legs, although May contended that each socket was on the same head but driven independently. Aerts conceded that the u-bolt could have been stretched in the accident, perhaps accounting for the inadequate torques he measured, but he also found that the overall length of the allegedly defective u-bolt was the same length as exemplar u-bolts provided by Ford and was within one millimeter of the length of another u-bolt from the truck. He conceded that he had no photographic proof of indentation of the axle caused by the asymmetrical flat portion of the u-bolt and that I never came back here to check that, but he opined that the asymmetrical manufacture, regardless of indentation of the axle housing, reduced the area of contact between the u-bolt and axle. The jury could infer that Ford would not have specified flattening of the curved end of the u-bolt?; which indisputably required an extra manufacturing step, unless Ford thought that procedure was needed. Aerts also testified that regardless of the shape of the u-bolt, Ford might have failed to tighten the u-bolt nuts to Ford's own torque specification because the air pressure on the tightening equipment was incorrect or for some other reason, thus explaining the inadequate torque and vibration damage he observed. His review of the accident scene photographs further persuaded him that the accident did not cause the u-bolt slippage and to opine that I don't think [the u-bolt] should have come loose with what I saw happen there on that street, Ford presented a strong defense, but ultimately the jury rejected it. Aerts's testimony does not present a case where there is simply too great an analytical gap between the data and the opinion proffered, [13] or where the expert's testimony amounted to nothing more than a recitation of his credentials and a subjective opinion. [14] We conclude that Ford's complaints about Aerts's testimony go to its weight, not its admissibility. The trial court therefore did not abuse its discretion in admitting Aerts's testimony.