Reining in the Substantial Factor Test for Causation

Enough Is Enough By Michele R. Kendus and Lucas W.B. Chrencik Reining in the Substantial Factor Test for Causation [The] invasion of one s mind by ready-made phrases can only be prevented if one is constantly on guard against them, and every such phrase anaesthetizes a portion of one s brain. George Orwell, Politics and the English Language, 1946. How much is enough? Plaintiffs attorneys say enough is enough in a matter of fact way to urge that any exposure will do. Defense attorneys say enough is enough, already! in exasperation at the ludicrous lengths to which the sub- stantial factor test for causation is taken. So how do we rein in the experts, judges, and juries to a sensible causation analysis? We must first be certain that we are on guard against the ready- made phrase substantially contributing factor uttered by plaintiffs counsel and their experts in various forms like substantial contributing cause, substantially contributed to, or was a substantial factor in causing. As the Pennsylvania judiciary has pointed out: Just because a hired expert makes a legal conclusion does not mean that a trial judge [or defense attorney] has to adopt it if it is devoid of common sense suppose an expert said that if one took a bucket of water and dumped it into the ocean, that was a substantial contributing factor to the size of the ocean. Gregg v. V-J Auto Parts, Inc., 596 Pa. 274, 286, 943 A.2d 216, 233 (2007) (quoting Summers v. Certainteed Corp., 886 A.2d 240, 244 (Pa. Super. Ct. 2005)). Courts and legal scholars alike have recognized misuse and abuse of the substantial factor test, to the extent that some argue against its continued application. See Sanders, Joseph, et al., The Insubstantiality of the Substantial Factor Test for Causation, 73 Mo. L. Rev. 63 (2008). Indeed, the Restatement (Third) of Torts: Liability for Physical and Emotional Harm, 26 (2010), seems to have abandoned the substantial factor test. Recognizing these potential and actual shifts in the law, a toxic tort defense attorney must have a firm grasp on the factual and legal principles of causation to prevent the case from being shoved into the substantial factor corner if it doesn t belong there. Likewise, the savvy defense attorney will understand the theories of factual and legal causation in order to build an effective defense against attempts to relax the burden of proof under the substantial factor test. This article provides the legal backdrop and a case example to build such effective defenses. Causation Analysis Back to the Basics The first step in a proper causation analy- Michele R. Kendus is a partner and Lucas W.B. Chrencik is an associate at Goodell, DeVries, Leech & Dann LLP in Baltimore. Ms. Kendus defends clients facing toxic tort, pharmaceutical, medical product liability, and medical malpractice claims. Mr. Chrencik focuses his practice in product liability and medical malpractice defense and is a member of the Young Lawyers Committee. 2013 DRI. All rights reserved. For The Defense January 2013 61

sis is to distinguish between factual causation and legal causation. The Restatement (Third) of Torts: Liability for Physical and Emotional Harm, 26 (2010), explains that [tort ious] [c]onduct is a factual cause of harm when the harm would not have occurred absent the conduct. The familiar but for test is the standard for determining factual cause, which is also described as Legal scholars have argued against continued use of the substantial factor test due to the overuse, abuse, and the confusion generated by it. a necessary condition for the outcome. Id. at cmt. b. Legal cause is described by the theory of proximate causation: the harm complained of must be the direct result of the risks presented by the tortious conduct. Restatement (Third) of Torts: Phys. & Emot. Harm, 29 (2010). Many jurisdictions have historically followed the so-called but for causation- in- fact test, that is, to constitute proximate cause there must be such a natural, direct, and continuous sequence between the negligence act [or omission] and the [plaintiff s] injury that it can reasonably be said that but for the [negligent] act [or omission] the injury would not have occurred. Stahl v. Metro. Dade County, 438 So. 2d 14, 17 18 (Fla. Dist. Ct. App. 1983) (citing Pope v. Pinkerton- Hays Lumber Co., 120 So. 2d 227, 230 (Fla. Dist. Ct. App. 1960), cert. denied, 127 So. 2d 441 (Fla. 1961), relying on Seaboard Air Line Ry. v. Mullin, 70 Fla. 450, 70 So. 467, 470 (1915)). This has proven to be a fair, easily understood and serviceable test of actual causation in negligence actions. Id. The substantial factor test initially arose to address specific situations involving multiple sufficient causes where the but for test fails to find liability. The classic case, Anderson v. Minneapolis, St. Paul & Sault Ste. Marie. Ry. Co., 146 Minn. 430, 179 62 For The Defense January 2013 N.W. 45 (1920), first applied the substantial factor test to a situation where two separate fires (one natural and one the result of negligence) merged and burned the plaintiff s property, but either fire alone would have been sufficient to cause the identical harm. In that case, the but for test would have reached an unfair result, so the court applied the rationale that if the negligently set fire was a material element in the property destruction, the tortfeasor would not escape liability. Id. at 439, 179 N.W. at 49. The Restatement adopted the substantial factor test, stated in Restatement (Second) Torts as the standard by which a defendant s conduct will be deemed a cause of the plaintiff s injuries: The actor s negligent conduct is a legal cause of harm to another if (a) his conduct is a substantial factor in bringing about the harm, and (b) there is no rule of law relieving the actor from liability because of the manner in which his negligence has resulted in the harm. Id. (citing Restatement (Second) of Torts 431 (1965); see also Borg- Warner v. Flores, 232 S.W.3d 765, 770 (Tex. 2007) ( [w]e have recognized that [c]om mon to both proximate and producing cause is causation in fact, including the requirement that the defendant s conduct or product be a substantial factor in bringing about the plaintiff s injuries. ); Moeller v. Garlock Sealing Technologies, LLC, 660 F.3d 950, 953 (6th Cir. 2011) ( [t]o prevail on a negligence claim, Kentucky law requires a plaintiff to prove that a defendant s conduct was a substantial factor in bringing about the harm. ). Comment a to the Restatement explains that the test was meant to add an additional element to the but for test, stating that it is not enough that the harm would not have occurred had the actor not been negligent the negligence must also be a substantial factor in bringing about the plaintiff s harm. Restatement (Second) of Torts 431 cmt. a (1965). Comment b explains that the test is not intended to supplant the but for analysis in cases where it is clear that the harm was caused by either the actor s negligence or some other cause, and the harm is not due to the combined effects of both. Id. at cmt. b. Section 432(2) of the Restatement (Second) adopts the Anderson analysis where two forces, one negligent and the other not, are each sufficient to bring about the same harm, and both are actively operating the actor s negligence may be found to be a substantial factor in causing the harm. Restatement (Second) of Torts 432(2) (1965). While some courts confine the substantial factor test only to those situations involving multiple sufficient causes, and maintain the but for test to determine factual causation, others have expanded it to supplant the but for test. Legal scholars have argued against continued use of the substantial factor test due to the overuse, abuse, and the confusion generated by it. See Restatement (Third) of Torts: Phys. & Emot. Harm 26 cmt. j (2010); see also Sanders, supra. The Restatement commentators note that [t]he substantial factor rubric is employed alternately to impose a more rigorous standard for factual cause or to provide a more lenient standard in a way that is inconsistent with the test adopted in the Restatement Second of Torts 431. Id. These authors convincingly argue that all situations can be resolved under a but for analysis with the incorporation of comparative responsibility, comparative contribution, and modification of joint and several liability to determine degrees of liability without disturbing the idea that causation in fact is an all- or- nothing proposition specific conduct is either a cause in fact, or it is not. Restatement (Third) Torts: Phys. & Emot. Harm 26 cmt. j, Reporter s Note (2010) (quoting Waste Magmt., Inc. v. S. Cent. Bell Tel. Co., 15 S.W.3d 425, 433 (Tenn. Ct. App. 1997)). The Substantiality Requirement Although not uniformly recognized, important to the concept of the substantial factor test is the notion that the effect of the allegedly negligent conduct must rise above the level of something that is merely more than nothing. Dixon v. Ford Motor Co., 206 Md. App. 180, 195, 47 A.3d 1038, 1048 (2012). See also Lohrmann v. Pittsburgh Corning Corp., 782 F.2d 1156, 1162 (4th Cir. 1986) (rejecting plaintiff s argument in an asbestos case that any evidence of workplace exposure raises a jury question as to whether the product contributed to the plaintiff s disease, requiring

instead a showing of more than a casual or minimum contact with the product). The Commentary to Restatement (Second) of Torts 431 elaborates on the substantiality requirement: The word substantial is used to denote the fact that the defendant s conduct has such an effect in producing the harm as to lead reasonable men to regard it as a cause, using that word in the popular sense in which there always lurks the idea of responsibility, rather than in the so-called philosophic sense, which includes every one of the great number of events without which any happening would not have occurred. Each of these events is a cause in the so-called philosophic sense, yet the effect of many of them is so insignificant that no ordinary mind would think of them as causes. Restatement (Second) of Torts 431 cmt. a (1965). Notwithstanding this substantiality requirement, some courts have accepted plaintiffs position that evidence of any exposure to the product at issue is sufficient to meet their burden of persuasion on causation, as long as an expert will repeat the substantial contributing factor mantra. In Flores, prior to being reversed by the Texas Supreme Court, the Texas Court of Appeals had stated [i]n the context of asbestos- related claims, if there is sufficient evidence that the defendant supplied any of the asbestos to which the plaintiff was exposed, then the plaintiff has met the burden of proof. Borg- Warner Corp. v. Flores, 153 S.W.3d 209, 213 (Tex. App. 2004) rev d, 232 S.W.3d 765 (Tex. 2007) (emphasis added). Reversing, the Texas Supreme Court in Borg- Warner Corp. v. Flores, 232 S.W.3d 765 (Tex. 2007), held that a plaintiff in an asbestos case may not simply establish that some exposure occurred. Id. at 773. Because most chemically induced adverse health effects clearly demonstrate thresholds, there must be reasonable evidence that the exposure was of sufficient magnitude to exceed the threshold before a likelihood of causation can be inferred. Id. The court required the plaintiff to show the threshold amount of asbestos exposure needed to cause asbestos related injuries and a showing that the plaintiff was, in fact, exposed to that threshold amount. Thus, the court rejected the theory that if the plaintiff can present any evidence that a company s asbestos- containing product was at the workplace while the plaintiff was at the workplace, a jury question has been established as to whether that product proximately caused the plaintiff s disease. Id. (citing favorably to Lormann v. Pittsburgh Corning Corp., 782 F.2d 1156, 1162 (4th Cir. 1986)). Put another way, the Flores court required the plaintiff to prove the dose of the plaintiff s exposure, and that such dose was sufficient to cause some injury. Like the Texas Supreme Court, other courts have begun to tighten the relaxed standard of proof born from the too broad application of the substantial factor test. Plaintiffs may find that they can no longer easily meet their burden of proof through the mere evidence of unmeasured exposure and the opinion of an expert who is simply parroting the ready-made phrase substantial contributing factor. Instead, these courts are requiring that the plaintiff provide evidence to quantify exposure and establish that the level of exposure was sufficient to cause injury. For example, two cases recently out of the courts of Pennsylvania and Maryland have elaborated on the type of evidence that plaintiffs must provide in order to permit the jury to determine the question of whether exposure to a product caused an individual s injury. Like Flores, both cases deal with asbestos exposure and whether a plaintiff s expert may testify that any exposure constitutes a substantial contributing factor to the plaintiff s injury. In Betz v. Pneumo Abex, LLC, 44 A.3d 27 (Pa. 2012), the plaintiff sought to offer the so-called each and every asbestos fiber expert opinion that: Asbestos- related mesothelioma, like other diseases induced by toxic exposures, is a dose response disease: each inhalation of asbestos- containing dust from the use of products has been shown to contribute to cause asbestos- related diseases, including mesothelioma. Each of the exposures to asbestos contributes to the total dose that causes mesothelioma and, in so doing, shortens the period necessary for the mesothelioma to develop. [E]ach exposure to asbestos is therefore a substantial contributing factor in the development of the disease that actually occurs, when it occurs. Id. at 31. The trial court excluded plaintiff s causation expert, appreciating the trial court s common sense question if all [that plaintiff s expert] could say is that a risk attaches to a single asbestos fiber [how is it] that he could also say that such risk is substantial when the [plaintiffs] may have been (and likely were) exposed to millions of other fibers from other sources including background exposure [?] Id. at 55. The Pennsylvania Supreme Court affirmed the trial court on the grounds that the opinion was not only fundamentally at odds with the substantial factor test, it was also at odds with the expert s own concession because one cannot simultaneously maintain that a single fiber among millions is substantially causative, while also conceding that a disease is dose responsive. See id. at 56. The court further reasoned: We do not think it is a viable solution to indulge in a fiction that each and every exposure to asbestos, no matter how minimal in relation to other exposures, implicates a fact issue concerning substantial- factor causation in every direct- evidence case. The result, in our view, is to subject defendants to full joint- and- several liability for injuries and fatalities in the absence of any reasonably developed scientific reasoning that would support the conclusion that the product sold by the defendant was a substantial factor in causing the harm. Id. at 56 57. In a similar more recent opinion, Maryland s Court of Special Appeals precluded an expert s opinion that every exposure to asbestos is a substantial contributing cause and so [ ] exposure [to the defendant s product] would be a substantial cause even if [the plaintiff] had other exposures. Dixon v. Ford Motor Co., 206 Md. App. 180, 196, 47 A.3d 1038, 1047 (2012). The court reasoned: Like the closely- related concept proximate cause, the term substantial contributing factor goes beyond the logically simple question of whether the defendant s action (or inaction) was a necessary or sufficient condition of harm to the plaintiff. Both proximity and substantiality describe whether the defendant s conduct has such an effect in For The Defense January 2013 63

producing the harm as to lead reasonable men to regard it as a cause, using that word in the popular sense, in which there always lurks the idea of responsibility[.] Restatement (Second) of Torts 431 (1965). Where the question of causation is probabilistic, substantiality and responsibility necessarily imply some test of magnitude, viz., how much Courts are requiring that the plaintiff provide evidence to quantify exposure and establish that the level of exposure was sufficient to cause injury. 64 For The Defense January 2013 must exposure have increased one s risk of harm in order to hold the responsible party liable? If risk is our measure of causation, and substantiality is a threshold for risk, then it follows as intimated above that substantiality is essentially a burden of proof. Moreover, we can explicitly derive the probability of causation from the statistical measure known as relative risk, as did the U.S. Court of Appeals for the Third Circuit in DeLuca v. Merrell Dow Pharmaceuticals, Inc., 911 F.2d 941, 958 (3d Cir. 1990), in a holding later adopted by several courts. For reasons we need not explore in detail, it is not prudent to set a singular minimum relative risk value as a legal standard. But even if there were some legal threshold, [plaintiff s expert] provided no information that could help the finder of fact to decide whether the elevated risk in this case was substantial. Id. at 193 95, 47 A.3d at 1046 47. Because the plaintiff s expert s opinion that every exposure to asbestos is a substantial contributing cause implied only that the plaintiff s exposure to asbestos increased her risk of developing mesothelioma by more than nothing, such an infinitesimal change in risk cannot suffice to maintain a cause of action in tort. Id. at 196, 47 A.3d at 1047. Accordingly, the Maryland Court of Special Appeals join[ed] with several other courts in requiring quantitative epidemiological evidence before permitting the jury to determine the question of whether the plaintiff s exposure caused her injuries. Id. at 197, 47 A.3d at 1048 (citing Bland v. Verizon Wireless, L.L.C., 538 F.3d 893, 898 (8th Cir. 2008); Lindstrom v. A-C Product Liability Trust, 424 F.3d 488, 498 (6th Cir. 2005); Mitchell v. Gencorp Inc., 165 F.3d 778, 781 (10th Cir. 1999); Moore v. Ashland Chem. Inc., 151 F.3d 269, 278 (5th Cir. 1998)) (emphasis added). The potential impact of these holdings on future toxic exposure cases is, for obvious reasons, huge. Attorneys must continue to provide the court with a thorough analysis of factual causation to persuade the court not to stray from the intent of the substantial factor test to limit, not expand, liability. Under the proper analysis, courts will no longer permit plaintiffs to shirk their burden of proof through nothing more than their expert s readymade phrase substantial contributing factor. Courts will demand that plaintiff s experts quantify the exposure and the injury (or increase in risk of injury) caused by the exposure to assist the jury in determining whether the exposure was a substantial contributing factor in causing the plaintiff s alleged injuries. Such a requirement only makes sense, because it removes from the purview of the expert an issue that ought to be within the sole purview of the fact finder. The concept of a substantially contributing factor is not one typically considered by physicians in a clinical setting to describe the etiology of disease. Indeed, every expert who parrots the words should be put to the test in deposition: Doctor, in your clinical practice have you ever gone about the task of determining if a certain factor substantially contributed to a patient s disease? The answer will undoubtedly be a wide-eyed No. The expert should next be made to explain what, then, he means when he utters those words. The answers compiled in various depositions in our practice range from my wife who is a lawyer explained that it meant each exposure must be capable of causing the same injury to according to Webster s, it is something that is measurable, significant and that things would be different absent it, and even the patently incorrect greater than 50 percent. Case Example Investigation and Case Work Up Before ever asking whether an exposure is a substantial factor in causing injury, discovery should be designed to define the injury, establish the onset of injury, quantify dose, and establish what particular injury occurs at certain doses. This inquiry will guide whether a substantial factor analysis is appropriate at all, or whether a stronger and more effective defense can be made that the exposure was not responsible for any injury, or only for a distinguishable part of the injury. This requires close work with defense experts and careful review of any prior testimony from the plaintiff s experts who may have described what injury occurs at particular doses. Additionally, exhaustive investigation of medical and other records to establish pre- exposure level of functioning and a chronology of other exposures or causative factors is key. As a case example, we present our experience dealing with experts in lead paint litigation filed by plaintiffs who allege that they were exposed to lead at a young age (typically between birth and six years old) from homes in Baltimore that contained deteriorated lead-based paint. In these cases, the plaintiffs claim that the lead exposure caused them to suffer a loss in intelligence quotient (IQ) and other neurocognitive deficits, academic and vocational difficulties and, ultimately, loss of earning potential. In many lead cases, the plaintiff lived in or visited numerous properties containing lead-based paint during the time that blood lead levels were measured. Blood lead levels (BLLs) are routinely checked by pediatricians as a screening measure between the ages of 18 months and three years, expressed in micrograms per deciliter ( µg/ dl ). Because the cases raise issues of multiple exposures to lead, as well as other factors that impact cognitive development, courts generally utilize the substantial factor test to determine whether exposure at an individual defendant s property caused the plaintiff s alleged injuries. See Bartholomee v. Casey, 103 Md. App. 34, 56, 651 A.2d

908, 918 (1994) ( Where the conduct of a defendant was a substantial factor in bringing about the suffering of an injury, such conduct will be deemed to have caused the injury. ) (citing W. Page Keeton, et al., Prosser And Keeton On Torts, 41, at 266 68 (5th ed. 1984 & Supp. 1988)). Typically, in an effort to meet the requirements of the substantial factor test, plaintiffs rely on the testimony of medical doctors. These experts offer expert opinions that the epidemiological literature finds an association between lead exposure and decreased IQ, as well as other neurocognitive functioning (general causation). The experts then simply extrapolate from the general literature to opine that the individual plaintiff s IQ would have been higher, and the neurocognitive deficits would not have been as significant if the plaintiff had not been exposed to lead. The experts typically apply a formula to calculate how many IQ points the individual lost based on his or her peak BLL. The medical expert will also offer a typical opinion that any house identified where the plaintiff lived or visited is a substantial contributing factor to both the elevated BLLs and neurocognitive deficits. The cases raise several questions regarding 1) whether the overall lead exposure caused or substantially contributed to cognitive deficits, 2) whether an individual defendant s property caused or substantially contributed to the elevated blood lead levels, and then 3) whether an individual defendant s property caused or substantially contributed to the cognitive deficits. The case example will focus on the second and third questions concerning the individual defendant s contribution. In our case, a plaintiff filed a claim against several defendant property owners, and ours was the only one financially viable to defend the claim. The evidence developed through discovery established chronology and documented blood lead levels, with our client s property identified as Property B (see Table 1, page 66). It was anticipated that the plaintiff s medical expert would opine in typical form that each property lived in or visited by the plaintiff was a substantial contributing factor to the elevated blood lead levels and resultant neurocognitive deficits, including IQ loss. A careful assessment of the facts developed in discovery prior to the expert s deposition revealed that this was a case that might not deserve to get shoved into a substantial cause corner, since the peak blood lead level of 18 µg/dl occurred prior to the plaintiff ever setting foot at the client s property. Our argument would be that our client could not be a cause in fact at all, at least for the decreased IQ, if the expert opined that the IQ loss was determined by the peak blood lead level. Knowing that in our jurisdiction the case would nonetheless be analyzed under the substantial cause rubric, we carefully set the stage to instruct the court why there can be no factual bases for the expert s substantial cause opinions. The Expert Deposition Armed with the knowledge from review of prior testimony that the expert had previously calculated IQ loss based on peak blood lead levels, and with the carefully detailed residential chronology learned through discovery, the deposition questions built a sequence to establish the expert s opinion that Property B did not cause or contribute to the earlier blood lead levels, including the peak, and that Properties A and C did contribute to all of the blood levels. The expert s opinion on loss of IQ was elicited as expected, based on peak BLL. The expert was also asked to detail the other neurocognitive deficits that he believed were caused or contributed to by the lead exposure. He was pushed to identify specific deficits described from the report of neurocognitive testing, and to provide his basis in the literature to say that a causal relationship had been established between that particular deficit and lead exposure. Concessions were also obtained regarding other factors that are causally associated with IQ loss and the specific neurocognitive deficits. Ultimately, he conceded that he could not say to a reasonable degree of medical probability that absent his lead exposure as a whole, plaintiff would not have any of the neurocognitive deficits identified. Rather, he could only say that the lead exposure contributed to his having them or exacerbated them. When the expert fell into the anticipated mantra of substantially contributed, he was asked to provide his definition of substantial contributing factor, which he testified meant of consequence. It was also known from prior testimony that the expert could not say within a reasonable degree of medical probability that injury occurs at a blood lead level of 5 µg/dl or under, so we obtained the same testimony regarding threshold for injury or in the expert s terms the level that is of consequence. Finally, the expert was asked to quantify the blood lead level caused by the plaintiff s exposure to Property B which Under the proper analysis, courts will no longer permit plaintiffs to shirk their burden of proof through nothing more than their expert s readymade phrase substantial contributing factor. he, of course, could not do. The testimony obtained set the stage for a motion to exclude the expert s baseless opinions. Because the expert conceded that he could not measure what the plaintiff s blood lead level would have been from exposure to Property B alone, there is no factual basis for him to leap to the conclusion that the property substantially contributed to plaintiff s blood lead levels and resultant injuries. It is equally conceivable that the plaintiff s exposure at Property B, where the highest documented BLL was 15 µg/dl contributed only 1, 2, 3 or 4 µg/dl (causing no injury at all) and that the ongoing exposure from the other properties accounted for the entire levels up to at least 10 µg/dl. Additionally, if the contributing properties alone caused the BLLs to elevate consistently to a level over 5 µg/dl, then the injury was sustained even if the plaintiff had not been exposed to Property B. With regard to the IQ loss, this is again an important lesson in distinguishing when substantial factor is or is not the correct test. It simply cannot be said that a subsequent exposure is a substantial con- For The Defense January 2013 65

tributing factor to an injury that occurred prior to the exposure. There should be no question that the defendant cannot be held liable for that defined injury. Focusing the argument on factual causation, the fact finder in this case could determine based on the facts that exposure from Property B had no effect or negligible effect Table 1. Property B Chronology Date of Testing Level (mcg/dl) Residential Address (undisputed by the parties) on the plaintiff s BLLs and injuries and the expert offered nothing that permitted him to leap to the opposite conclusion, presented in the guise of his opinion. The stage was set, therefore, to argue that he should not be permitted to offer his naked opinion that exposure at the property substantially contributed to anything. Once the opinion Visitation Properties (undisputed by the parties) 1/19/93 10 (v) Property A Property C 6/14/93 17 (c) Property A Property C 8/27/93 18 (c) Property A Property C 10/1/93 14 (v) Property A Property C 3/29/94 11 (v) Property A Property C 4/29/94 11 (c) Property A Property C 1/30/95 10(c) Property A Property C 5/3/95 10(c) Property B Property A and C 8/7/95 13 (c) Property B Property A and C 1/30/96 15(c) Property B Property A and C is excluded, the plaintiff is without the necessary evidence to meet his burden of proof. Conclusion Legal scholars and the courts alike are recognizing that the substantial factor test has been so loosely applied that it has strayed far from its original intent, and many are prepared to reverse that course. Defense attorneys must continue the push to rein in the relaxed standards on plaintiffs burden to prove causation. A common sense approach to causation issues that urges the courts to move back to the basics of factual and legal causation analysis provides the framework by which plaintiffs should be required to quantify just how much is enough before the question of causation can ever reach a jury. We must be on guard, and we must place the courts on guard, so that the minds of the legal community do not become anesthetized by the ready-made phrase substantial contributing factor. 66 For The Defense January 2013