Because the factual background and procedural history of this case have been set out at length in other reported opinions, we recite only those facts necessary to our decision here. The previous decisions rendered in this case are, in chronological order: Ayala v. Joy Mfg. Co., 580 F. Supp. 521 (D.Colo. 1984) ( Ayala I); Ayala v. Joy Mfg. Co., 610 F. Supp. 86 (D.Colo. 1985) ( Ayala II); Ayala v. Joy Mfg. Co., 877 F.2d 846 (10th Cir. 1989) ( Ayala III), rev'g, 610 F. Supp. 86; Ayala v. United States, 771 F. Supp. 1097 (D.Colo. 1991) ( Ayala IV); Ayala v. United States, 980 F.2d 1342 (10th Cir. 1992) ( Ayala V), rev'g, 771 F. Supp. 1097; Ayala v. United States, 846 F. Supp. 1431 (D.Colo. 1993) ( Ayala VI). In our most recent decision in this case, we held that the technical assistance claim was not barred by the discretionary function exception to the Federal Tort Claims Act (FTCA), 28 U.S.C. § 2680(a).

The concept of intervening cause is part of the framework for determining proximate cause for negligent conduct. See, e.g., White v. Caterpillar, Inc., 867 P.2d 100, 109 (Colo.Ct.App. 1994); Ayala v. United States, 846 F. Supp. 1431, 1441 (D. Colo. 1993); see also Restatement (Second) of Torts § 441 (1965) (defining intervening cause as one that produces harm to another after the defendant has committed a negligent act or omission and identifying rules for determining whether the intervening cause "prevents the actor's antecedent negligence from being a legal cause" of another's harm). Under Colorado law, trespass is not grounded in negligence, see Burt v. Beautiful Savior Lutheran Church, 809 P.2d 1064, 1067 (Colo.Ct.App. 1990), but rather is a strict liability tort for which proximate causation is established by proof that the defendant intentionally undertook an activity or activities that in the usual course of events caused the trespass.

Instead of explaining how Colorado law could permit his claim to survive summary judgment, Mathison relies primarily on cases from other jurisdictions. The cases applying Colorado law that he cites only restate the legal definition of causation, see Dmitruk v. George & Sons' Repair Shop, Inc., 217 F. App'x 765, 769 (10th Cir. 2007) (unpublished); Ayala v. United States, 846 F. Supp. 1431, 1441 (D. Colo. 1993), or concern the inapposite issue of when an expert is reliable under Federal Rule of Evidence 702, see Etherton v. Owners Ins. Co., 35 F. Supp. 3d 1360, 1366-67 (D. Colo. 2014). Mathison also charges that an affidavit submitted by the government's expert is unreliable, misleading, and rooted in fraud. But Mathison bears the burden of proof on the issue of causation, and because he has not presented evidence sufficient to meet that burden, any flaws in the expert's affidavit are irrelevant to the legal issue before us.

Duty is a question of law determined by looking to several factors, including "the risk involved, the foreseeability and likelihood of injury as weighed against the social utility of the actor's conduct, the magnitude of the burden of guarding against injury or harm, the consequences of placing the burden upon the actor, and any additional elements disclosed by the particular facts of the case." Ayala v. U.S., 846 F.Supp. 1431, 1437 (D. Colo. 1993), aff'd, Ayala v. U.S., 49 F.3d 607 (10th Cir. 1995); Bd. of County Com'rs of County of La Plata v. Moreland, 764 P.2d 812, 816, 1988 WL 125422 (Colo. 1988) (recognizing a duty may be derived by either statute or common law). Doc. 46 at 70.

I agree with defendants. "In Colorado, the elements of a negligence claim consist of . . . a duty owed by the defendant to the plaintiff, a breach of that duty, injury to the plaintiff, and a proximate cause relationship between the breach and the injury."Ayala v. United States, 846 F. Supp. 1431, 1437 (D. Colo. 1993), aff'd, 49 F.3d 607 (10th Cir. 1995). "A negligence claim fails where the law does not impose a duty on the defendant to act for the plaintiff's benefit."

A "legal duty to use reasonable care arises in response to a foreseeable and unreasonable risk of harm to others." Ayala v. United States, 846 F. Supp. 1431, 1440 (D. Colo. 1993) (citing Quintana, 827 P.2d at 519). The "driver of a vehicle is not negligent because of a sudden failure of the vehicle's equipment if that person could not have reasonably foreseen the sudden equipment failure and that person has done all that a reasonably careful person would have done."

1997); Connes v. Molalla Transp. Sys., Inc., 831 P.2d 1316, 1320 (Colo. 1992); Ayala v. United States, 846 F. Supp. 1431, 1437 (D. Colo. 1993). Plaintiffs contend that Scripto was negligent in: (1) not designing a more child-resistant Aim N Flame; and (2) failing to provide adequate warnings to consumers concerning the inherent dangers associated with the Aim N Flame. (Pls.' Resp. at 3.) Scripto maintains that it is entitled to summary judgment on plaintiffs' negligence claims because: (1) the law does not impose a duty on manufactures to make adult products such as the Aim N Flame child-resistant; and (2) its warning regarding the dangers of the Aim N Flame were adequate as a matter of law. (Def. Scripto's Br. at 9, 11-12.