Twyman v. GHK
An Overdue Look into the Sufficiency of Causation Evidence in Toxic Tort Litigation
By Chad R. Reineke

An experienced oil and gas attorney once jokingly told me, “when the cows die, the oil company pays!” While such a statement, at first glance, appears to be the biased thinking of a defense counsel veteran; one does not have to search through the Pacific Reporters very long to find some truth in the statement. A particular example being Sun Oil Co. v. Hoke, decided by the Oklahoma Supreme Court way back in 1946.1 There, the plaintiff’s contention was that the defendant oil producer was “negligent and careless in allowing large quantities...of deleterious substances to escape and flow over the land into plaintiff’s fresh water pond poisoning and polluting same; that his livestock drank said poisoned and polluted water and that he was damaged as a result thereof.”2

At trial, plaintiff’s star witness was a ranch hand who witnessed cows drinking from the pond and subsequently becoming sick. As any “expert” would, the ranch hand began to investigate. According to his trial testimony, he saw a “small flow” running from the defendant’s reserve pits into the pond, tasted it, and ascertained that it was salty.3 Unbeknownst to the ranch hand, he was actually conducting a rudimentary form of the medical technique known as differential diagnosis. The ranch hand had observed the cows’ illness and naturally began to eliminate possible causes of such illness — until identifying the most likely cause. Operating under the assumption that the “salty” water was capable of causing illness to cattle, he settled on their drinking from the pond into which that salt water flowed as the ultimate cause of their death.

While basing such a conclusion on the unverified assumption that the “salty” water is capable of causing cattle illness would undoubtedly be considered unreliable methodology by today’s standards, apparently in 1946 it was reliable enough for the Oklahoma Supreme Court to conclude that “it cannot be said that there was material variance or failure of proof upon plaintiff’s theory of the case...and would not militate against the theory that they [the cows] drank poisoned and polluted water...”4 In other words, the “cows die, the oil company pays!”

Some 50 years later, the Oklahoma Supreme Court adopted Daubert v. Merrell Dow Pharmaceuticals as the controlling standard with regards to the admissibility of expert testimony inside Oklahoma courtrooms.5 Such standards were intended to ensure the reliability of scientific testimony ultimately allowed to reach the jury’s ears. Relevant to the present discussion, “when the cows die,” Daubert is intended to ensure that the “oil company pays” only when reliable testimony has established that the oilfield operations were, in fact, the cause of the cows death. Unfortunately, word of such jurisprudential developments had not yet reached the Washita County courtroom by the time Twyman v. GHK made it to trial.6

The facts of the Twyman case were strikingly similar to those in Sun Oil way back in 1946. The Twymans operated a dairy farm on property adjacent to oilfield operations conducted by both GHK and Mobil. Three years prior to bringing their lawsuit, the plaintiffs began experiencing a series of health problems with their dairy cows. As these problems worsened, some of those cows began to die. The Twymans made some initial efforts to identify the cause of these problems, however, the illnesses continued. Finally, after losing 19 of their cattle, the Twymans sold the remainder of the herd at auction. Three years later, the Twymans filed suit against GHK and Mobil — alleging that “pollutants” had migrated from the defendants’ reserve pits into a water well located on the Twymans’ property. The underlying theory being that this “toxic contamination” of their well water had caused the sickness and ultimate death of their dairy cows.7

During the course of the trial, the Twymans were given great leeway in putting forth extremely questionable testimony from numerous experts asserting that the defendants’ “contaminants” were both capable of, and ultimately responsible for, causing the Twymans’ cattle losses. Obviously influenced by such testimony, a Washita County jury returned a verdict in favor of the Twymans — in the amount of $7.2 million. Stunned by such a verdict, the defendants immediately moved for a judgment notwithstanding the verdict, new trial, and — in the alternative — remitter of damages to $250,000.8 The trial court denied both the motion for judgment notwithstanding the verdict and new trial; stating that while the plaintiffs’ case on liability “hung by a thread,” they put on “sufficient evidence of causation” for the case to go to the jury.9

Following the trial court’s decision to allow the verdict against the defendants to stand, GHK and Mobil immediately appealed to the Oklahoma Court of Civil Appeals. Here it is important to note that neither GHK nor Mobil ever conceded that their oilfield operations resulted in any contamination of the Twymans’ well. Nor did they concede that the well was contaminated at all.10 The focus of the appellate court, however, was upon the evidence offered to establish the well water as the ultimate cause the cows’ illness. Thus, the focus of this article is upon that same evidence.

While it is clear, in Oklahoma, that Daubert is indeed that controlling standard with regards to the admissibility of expert testimony; the application of those standards is still somewhat murky — especially in cases, such as Twyman, which allege injury as a result of toxic contamination. A plaintiff who claims to be a victim of toxic contamination carries the burden of establishing that it was, in fact, the defendant’s contaminant that caused whatever toxic injury they are suffering from.11 This burden of causation is actually two-fold. Meaning, the plaintiff carries the dual burden of establishing both general and specific causation. Put another way, the plaintiff must not only prove that the alleged toxic contaminant is generally capable of causing the injury complained of (general causation), but also that their specific injury resulted from contact with that particular toxic contaminant (specific causation).12 Ultimately, it is this duty to establish both general and specific causation that necessarily becomes the focus of most toxic tort lawsuits. Ultimately then, it was this duty that became the focus of the Twyman appeal.13

As explained by the appellate court, the Twymans’ burden of establishing both general and specific causation could only be satisfied through testimony derived from several disparate scientific disciplines beyond the understanding of the average juror.14 Necessarily then, the Twymans put forth testimony from a number of expert witnesses in an attempt to prove their belief that pollutants from the defendants’ reserve pits caused their cattle losses. Specifically, the plaintiffs called multiple experts to testify to, what the appellate court termed, their “synergism” theory.15

This synergism theory was a combination —no pun intended — of the following assumptions: 1) that heavy metals, magnesium, and other unnamed components made their way from the defendants’ reserve pits to the plaintiffs’ water well, 2) that the cattle then drank the “polluted water,” and 3) that the dairy cows became sick from the combined effect of these otherwise individually safe components.16 (Because water testing had shown that the level of heavy metals present in the Twymans’ well water was below that of safe drinking water levels, the scientists’ theory had to be that the combined effect of otherwise safe levels of heavy metals was toxic to the bacteria in the cows’ digestive system.) This synergism theory was arrived at through a process known as differential diagnosis.

Differential diagnosis is a clinical technique of elimination, by which the identity of the cause of a medical problem is ascertained by systematically eliminating likely causes until the most probable cause is isolated.17 At the risk of oversimplification, differential diagnosis is best described as a process of “ruling in” and “ruling out.” Using such a process, the Twymans’ experts attempted to “rule in” the synergistic effect of heavy metals as the cause of the cows’ sickness — while at the same time “ruling out” all other potential causes.18 While such a technique stems from the clinical practice of medicine, its acceptance and reliability is gaining favor inside the courtroom as well.19

The utility of differential diagnosis in the practice of medicine, however, differs greatly from its utility in toxic tort litigation. The practice of medicine is a process of trial and error aimed at the clinical goal of therapy. The ultimate aim of litigation, on the other hand, is the ideological identification of conclusory facts used for the purpose of assigning liability to those found to be responsible for a resulting injury. Because of these differences, a careful balancing of the various implications of using differential diagnosis, to establish causation, in tort litigation is necessary. The interests of plaintiffs being able to prove their cause of action must be weighed against the interest of imposing strict safeguards on the introduction of scientifically unreliable diagnostic testimony. Thus the question becomes: To what degree should Oklahoma courts pass judgment on the methods and conclusions of medical and scientific professionals when gauging the reliability and relevance of their clinical practices inside the courtroom?

This was precisely the question called to the attention of the appellate court in Twyman v. GHK. A question which was left relatively unanswered by the Oklahoma Supreme Court following Christian v. Gray.20 This despite the fact that, Christian too, involved allegations of toxic contamination arrived at through differential diagnosis. The pronouncements of the Supreme Court, in Christian, made clear that Daubert is undoubtedly the controlling standard with regards to the admissibility of expert testimony in civil cases.21 However, the court failed to set forth any real conclusions as to the admissibility of differential diagnosis testimony under those standards. Because the plaintiffs, in Christian, failed to adequately develop the issue of general causation at the trial court level, the Supreme Court was provided a loop hole by which they could avoid a determination as to whether differential diagnosis is even capable of establishing such causation. Instead, the court more or less passed on the subject by simply noting that not all courts agree as to what constitutes reliable methodologies for establishing general causation.22

After sidestepping the general causation issue, the Christian court next turned to the issue of specific causation. Again, the court avoided a determination by simply noting the inconsistencies of other courts when assessing the reliability of differential diagnosis.23 Bottom line: Because of an undeveloped record at the trial court level, the Christian court was allowed to leave the determination as to the admissibility of differential diagnostic testimony for another day.24 As a result, the Washita County District Court had little guidance by which to measure the reliability of the Twymans’ “synergism” theory. As a result, the jury was allowed to hear testimony which never should have made it before them. As a result, the question of whether differential diagnosis is capable of satisfying admissibility requirements, when employed to establish causation, was finally called to the attention of Oklahoma Court of Civil Appeals.

Because differential diagnosis is a discipline finding its basis in medical science, any discussion must begin with the requirements of Daubert, as adopted by the Oklahoma Supreme Court. Under Daubert, the testimony of an expert witness is admissible only if it is both reliable and relevant. Thus, the court must make two individualized determinations about any proffered expert testimony. The trial court must first determine whether the reasoning or methodology underlying such testimony is reliable, as well as, whether or not that reasoning or methodology can properly be applied to the facts at issue.25

To assist the trial court in making such determinations, Oklahoma appellate courts have specifically endorsed the checklist of factors, used by the Daubert court itself, to judge a particular expert’s methodology and reasoning.26 Those factors include: 1) Can the theory or technique be, or has it been, tested; 2) Has the theory or technique been subjected to peer review and publication; 3) Is there a known or potential rate of error...and the existence and maintenance of standards controlling the technique’s operation; and 4) Is there widespread acceptance of the theory or technique within the relevant scientific community.27 Armed with this checklist, the Court of Civil Appeals set out to make a determination as to relevance and reliability of the Twymans’ differential diagnostic based synergism theory. Armed with this checklist, the Court of Civil Appeals finally provided a framework by which the utility of differential diagnosis inside the courtroom may be measured.

The appellate court began its inquiry by focusing on the lack of reliability of the Twymans’ proof of general causation. Because water tests failed to reveal anything over safe levels of heavy metals, the Twymans’ experts relied heavily upon the synergistic effect of those metals. On cross-examination, the Tywmans’ experts acknowledged that this theory was developed by “everyone working on the case” and could not be attributed to any one individual.28 More importantly, counsel for the defendants was able to establish that plaintiffs’ experts could not identify anyone else in the scientific community advancing such a theory.29 Nor could they identify the specific heavy metals which they contended combined to have a toxic effect on the cattle.30 Reviewing such testimony, the appellate court made several important observations with regards to the reliability of the synergism theory to prove general causation — observations which were apparently overlooked by the trial court.

First, the plaintiffs presented no evidence of any scientific literature supporting the synergism theory with respect to the components involved and their effect on animals. Second, there was no mention of any other scientist outside of the plaintiffs’ collection of experts advancing such a theory. Third, the Twymans’ experts could offer no evidence that this particular synergism theory had ever been tested. Finally, there was no indication that the theory has general or widespread acceptance within the veterinary community.31 Essentially, the appellate court measured the synergism theory against the aforementioned Daubert standards of reliability — and found it lacking.32

Because the plaintiffs’ general causation testimony was found unreliable, it necessarily should have been excluded at the trial court level. As concluded by the appellate court, without such testimony, the Twymans failed to meet their burden of establishing that the combined effect of otherwise safe levels of heavy metals is capable of causing illness in dairy cows.33 As a result, the Twymans failed to establish the requisite causal nexus between any action by GHK and Mobil and their losses. While such a conclusion resulted in a significant victory for the defendants in this particular case, the court unfortunately left open the door for future attempts to prove general causation through differential diagnosis.

The conclusion that the court was hinting at, but failed to specifically state, is that differential diagnosis is all together incapable of establishing general causation.34 This is best explained by looking at differential diagnosis for what it truly is. It is a clinical process employed by physicians — or in this case veterinarians — to determine from what disease a patient — or cow — suffers. By comparing the cows’ symptoms to symptoms associated with known diseases, the plaintiff’s veterinarians attempted to identify the particular disease that best explains the symptoms exhibited by the Twymans’ cows.

The resulting conclusion, however, speaks only to specific causation.35 Put another way, differential diagnosis only matches exhibited symptoms with known diseases. General causation, however, first requires a showing that the contaminant thought to be causing the symptoms is even capable of causing the disease in question. Therefore, differential diagnosis is in no way relevant to the general causation question. Even more troubling is lack of reliability which results from employing differential diagnosis to establish general causation. A scientist employing differential diagnosis to establish general causation necessarily operates on the presumption that the substance they are “ruling in” is capable of producing the harmful effect.36 As noted by the Twyman court, this presumption effectively forecloses any reliability in the process.37

Recognizing that differential diagnosis lacks both the relevancy and reliability requirements, of Daubert, when employed to prove general causation; the Twyman court looked for any alternative evidence explaining how the plaintiffs’ experts were able to “rule in” the combined effect of heavy metals as capable of causing illness in cattle. As explained by the court itself, “where differential diagnosis is used to show specific causation that party has also provided independently reliable evidence that the allegedly dangerous drug or substance had harmful effect, i.e. general causation was also shown.”38 Again what the court was hinting at, but never specifically said, was that some other scientifically valid methodologies — aside from differential diagnosis — must be employed to establish general causation.39

As the Twyman opinion states, however, there are some circumstances in which the general causation requirement may be excused altogether.40 When exactly these circumstances exist, however, is a question that was left somewhat unanswered. Instead, the Twyman court simply noted that the plaintiffs had failed to show that the requisite circumstances existed which would excuse such a showing.41 What the court inferred, however, is that a plaintiff will be relieved of the burden of showing general causation when a close temporal relationship between the plaintiff’s exposure to a supposedly toxic substance and the onset of the illness or injuries exists.42 Such an inference can be drawn from the fact that the Twyman court specifically addressed the fact that no water tests were conducted until several years following the cattle losses. Because no water test were performed at the time the cows became sick, the Twymans’ experts could only speculate as to what metals the cattle were exposed to — assuming they were exposed at all. Had the Twymans been able to establish high toxicity levels in the well water at the time the cows became sick, they would have successfully established a close temporal link between exposure and symptom.43

This is precisely the type of evidence the appellate court was looking for. Had the Twymans been able to put forth such evidence, they more than likely would have been excused of a showing of general causation. Without such evidence, however, the opinion evidence as to the harmful nature of the heavy metals was correctly excluded as being unreliable.

Despite its lack of relevance and reliability with regards to general causation, differential diagnosis is ordinarily admissible to show specific causation. Used in its proper context, differential diagnosis becomes both relevant and reliable. Concerning what did not cause a particular disease — i.e. “ruling out” other potential causes - the technique is widely used in the medical field.44

In much the same manner, the effectiveness of differential diagnosis for the purpose of matching symptoms to possible effects — i.e. “ruling in” the most probable cause — has been both peer reviewed and tested.45 Additionally, many books have been published explaining the process in both contexts. Most importantly, when properly employed, differential diagnosis enjoys widespread acceptance throughout the medical community.46 This acceptance stems from the fact that, once a showing of a correlation between a particular substance and a particular disease has been made, differential diagnosis has proven to be an extremely reliable method of isolating a particular substance as the probable cause of that disease.47 Thus, the Twymans’ experts were employing relevant and reliable methodology to prove specific causation. Those same experts, however, failed to properly employ that methodology. Ultimately then, it was the implementation of the differential diagnosis, and not the methodology itself, that the court found lacking with respect to specific causation.

Essentially, the Twymans’ experts got only half of the equation right. While differential diagnosis was used to “rule in” the synergism theory, it was not effectively used to “rule out” other more likely causes. Most notable was the Twymans’ poor management of their dairy farm. As pointed out by defense counsel, an experienced veterinarian visited the Twymans’ farm prior to the filing of the lawsuit and provided them with a written report concluding that their feeding regimen was improper and could be causing the weight loss in their herd.48 Both of the Twymans’ experts admitted on cross-examination that they had failed to look at or recognize this report.49 Thus, they failed to properly account for dairy management — which according to their own testimony is “the first thing you look at” — in their performance of differential diagnosis.50 As explained by the appellate court, “[the experts] failed to consider another possible cause for the cows’ health problems when proceeding through the differential diagnosis. [Their] diagnostic methodology was, therefore, at best, suspect.”51

Essentially, the court was stating that while they accept differential diagnosis as a valid method for establishing specific causation, experts employing such a method must properly examine all likely causes. Because the Twymans’ experts failed to do so, their implementation of an accepted practice was found to be unreliable.

The Twyman court makes clear the acceptance of differential diagnosis to establish specific causation inside Oklahoma court rooms. What remains unclear following the decision is to what degree of medical certainly must an expert “rule out” all other potential causes in order for their diagnosis to be considered reliable? Because the Twymans’ experts failed to properly consider something so glaring as dairy management, the court was relieved of the duty of answering such a question. For now, all we know is that failure to consider what even the testifying expert admits is the “first thing you look at” will leave a plaintiffs’ specific causation evidence lacking.

Much like the ranch hand in Sun Oil v. Hoke, the Twymans’ experts relied on the assumption that their “isolated cause” was capable of causing death to cattle. Much like the trial court in Sun Oil, the trial court, in Twyman, was willing to overlook such an assumption. Luckily, however, this is where the similarities between the two cases ended. Unlike the appellate court in 1946, the Twyman court was unwilling to simply affirm the trial courts conclusion that “the cows died” so the “oil company pays.” Instead, the court confronted, for the first time in Oklahoma, the use of differential diagnosis in toxic tort litigation. This is not to say that all questions regarding the sufficiency of differential diagnosis have been answered. Twyman v. GHK, however, has provided valuable insight into what is now required of plaintiffs who seek to implement the technique to prove causation.

Following Twyman, it is clear that differential diagnosis, by itself, cannot sufficiently establish general causation. An expert employing the technique must reliably demonstrate that they have done something more than “rule out” other potential causes. Rather, they must now explain how they were able to “rule in” the substance in question. Thus, when faced with such differential diagnostic testimony, defense counsel should demand “hard science” on the issue of general causation. The plaintiff should be required to show published and peer-reviewed scientific studies establishing a statistically significant link between the suspected contaminant and the suspected disease. This is the only way to ensure reliable testimony as to whether or not the substance in question is capable of causing the plaintiff’s injuries.

Plaintiffs will argue that such a conclusion leaves the “first plaintiff” to suffer from a particular disease causing contaminant with no means of establishing their prima facie case — as no scientific studies as to the contaminants harmful effects would yet exist. Relief from such a dilemma is provided to plaintiffs as long as a close temporal relationship exists between exposure to the isolated cause and the onset of symptoms or illness. In such instances, general causation will be excused and plaintiffs may proceed directly to a showing of specific causation. Thus, a balance is struck between the interests of plaintiffs being able to prove their cause of action, and the interests of defendants being able to ensure the introduction of reliable diagnostic testimony.

Finally, even if plaintiffs can produce hundreds of studies showing a statistically significant correlation between a contaminant and a disease, or in the alternative a close temporal relationship between exposure to the contaminant and onset of disease, they must also prove that the particular contaminant caused the disease in the instant case. Because clinical medicine constitutes the relevant field of study as to specific causation, testimony based on a properly performed differential diagnosis here satisfies Daubert’s relevancy requirement. Because the technique is so widely used in the medical community to evaluate the most likely cause of a patient’s symptoms, differential diagnosis also satisfies the reliability requirement when used to establish specific causation.

1. Sun Oil Co. v. Hoke, 1946 OK 30, 169 P.2d 753.
2. Id. at ¶ 3, 169 P.2d at 754.
3. Id. at ¶ 11, 169 P.2d at 755.
4. Id. at ¶ 19, 169 P.2d at 756.
5. See Christian v. Gray, 2003 OK 10, 65 P.3d 591.
6. Twyman v. The GHK Corp., 2004 OK CIV APP 53, 93 P.3d 51.
7. Id. at ¶ 3, 93 P.3d at 53.
8. Id. at ¶ 5, 93 P.3d at 54.
9. Id.
10. Id. at ¶ 28, 93 P.3d at 57.
11. Mason v. State ex rel. Board of Regents of University of Oklahoma, 2000 OK CIV APP 33, 23 P.3d 964.
12. See Starley v. Velsicol Chemical Corp., 855 F.2d 1188 (6th Cir. 1998).
13. Twyman at ¶ 28, 93 P.3d at 57. (“While GHK and Mobil contest the entire evidentiary trial from well site to the cows’ demise, we need only look to the evidence Twymans relied on to prove the well water was the cause of the cows’ illness.”)
14. Id. at ¶ 21, 93 P.3d at 56.
15. See Id. at ¶ 31, 93 P.3d at 58.
16. Id. at ¶ 29, 93 P.3d at 58.
17. Id. at ¶ 33, 93 P.3d at 58.
18. Christian v. Gray, 2003 OK 10, 28, 65 P.3d 591. (“A reliable differential diagnosis typically is performed after physical examinations, the taking of medical histories, and the review of clinical tests, including laboratory tests, and generally is accomplished by determining the possible cause for the patient’s symptoms and then eliminating each of these potential causes until reaching one that cannot be ruled out, or determining which of those that cannot be excluded is the most likely.”)
19. See In Re Paoli Railroad Yard PCB Litigation, 35 F.3d 717, 758 (3rd Cir. 1994). (“[differential diagnosis] has widespread acceptance in the medical community, has been subject to peer review, and does not frequently lead to incorrect results.”)
20. Christian v. Gray, 2003 OK 10, 65 P.3d 591.
21. See Id. at ¶ 14, 65 P.3d at 600. (“Today we likewise adopt Daubert and Kumho as appropriate standards for Oklahoma trial courts in deciding the admissibility of expert testimony in civil cases.”)
22. Id. at ¶ 26, 65 P.3d at 604.
23. Id. at ¶ 33, 65 P.3d at 606.
24. Id. at ¶ 20, 65 P.3d at 602. (“The reliability of an expert’s methods, in this context, involves medical science and its methods. In our case today, is the doctor’s opinion on causation based upon medical science of method? A complete answer to this question, as we now explain, needs additional facts to be developed by the parties in the trial court.”)
25. Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579, 592-593, 113 S.Ct. 2986, 125 L.Ed.2d 469 (1993).
26. Twyman at ¶23, 93 P.3d at 57. See also Christian at ¶ 8, 65 P.3d at 597-598.
27. Twyman at ¶ 23, 93 P.3d at 57.
28. Id. at ¶ 31, 93 P.3d at 58.
29. Id.
30. Id.
31. Twyman at ¶ 32, 93 P.3d at 58.
32. Twyman at ¶ 29, 93 P.3d at 58. (“For the following reasons we find these theories without sufficient scientific basis to be reliable and therefore, in accordance with Daubert and Christian, should not have been presented to the jury.”)
33. Twyman at ¶ 52, 93 P.3d at 61.
34. In Re Breast Implant Litigation, 11 F.Supp.2d 1212, 1230 (D.Colo. 1998).
35. Cavallo v. Star, 892 F.Supp. 756, 771 (E.D. Va. 1995).
36. Hall v. Baxter Healthcare Corp., 947 F.Supp. 1387, 1413 (D. Or. 1996). (“Differential diagnosis does not by itself prove the cause, even for the particular patient. Nor can the technique speak to the issue of general causation. Indeed, differential diagnosis assumes that general causation has been proven for the list of possible causes it eliminates.”)
37. Twyman at ¶ 34, 93 P.3d at 58.µ
38. Id. at ¶ 35, 93 P.3d at 58-59.
39. Id. at ¶ 41, 93 P.3d at 59-60. (“In the absence of some independently reliable evidence that the well water caused the harm, Dr. Page’s opinion falls short of Daubert’s admissibility standards.”)
40. Id. at ¶ 36, 93 P.3d at 59. (“If expert testimony is necessary to show cause of an injury from exposure to a toxin, the testimony of the expert should reveal a reliable method for determining the quantity of the toxin necessary to cause injuries of the type experienced by plaintiff (general causation), unless plaintiff can show that the circumstances are such that general causation should not be necessary.”)
41. Id. at ¶ 37, 93 P.3d at 59.
42. Id. at ¶ 40, 93 P.3d at 59.
43. Id. at ¶ 41, 93 P.3d at 59.
44. Michael B. Kent Jr., Daubert, Doctors and Differential Diagnosis: Treating Medical Causation Testimony as Evidence, 66 Def. Couns. J. 525, 533 (1999).
45. Id.
46. Id.
47. Id.
48. Twyman at ¶ 34, 93 P.3d at 58.
49. Id.
50. Id. at ¶ 33, 93 P.3d at 58.
51. Id. at ¶ 34, 93 P.3d at 58.

About the Author

Chad R. Reineke is an associate at the Oklahoma City law firm of Crowe & Dunlevy. His practice is concentrated primarily in the area of oil and gas litigation. He holds a J.D. from OCU School of Law, where he received both the Nesbitt Energy Law Award and Outstanding Oil & Gas Related Paper by a Law Student Award from the Mineral Lawyers Society of Oklahoma City.