Boos v. General Motors CA4/1

CourtCalifornia Court of Appeal
DecidedJanuary 30, 2026
DocketD086601
StatusUnpublished

This text of Boos v. General Motors CA4/1 (Boos v. General Motors CA4/1) is published on Counsel Stack Legal Research, covering California Court of Appeal primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Boos v. General Motors CA4/1, (Cal. Ct. App. 2026).

Opinion

Filed 1/30/26 Boos v. General Motors CA4/1 NOT TO BE PUBLISHED IN OFFICIAL REPORTS California Rules of Court, rule 8.1115(a), prohibits courts and parties from citing or relying on opinions not certified for publication or ordered published, except as specified by rule 8.1115(b). This opinion has not been certified for publication or ordered published for purposes of rule 8.1115.

COURT OF APPEAL, FOURTH APPELLATE DISTRICT

DIVISION ONE

STATE OF CALIFORNIA

CHARMAINE ANTOINETTE BOOS, D086601

Plaintiff and Appellant,

v. (Super. Ct. No.: CVPS2303157) GENERAL MOTORS LLC,

Defendant and Respondent.

APPEAL from a judgment of the Superior Court of Riverside County, Manuel Bustamante, Judge. Reversed. MLG Attorneys at Law, Jonathan A. Michaels, Samuel Crocket and Drew Morgan for Plaintiff and Appellant. Dykema Gossett, Dommond E. Lonnie and Nicholas O. von der Lancken; Bush Seyferth and Derek J. Linkous, for Defendant and Respondent. Charmaine Antoinette Boos sued General Motors LLC (GM), alleging that injuries she sustained in a collision were attributable to defects in airbags mounted in her GM-produced car. GM filed a motion for summary judgment. The trial court granted the motion and entered judgment accordingly. Boos appeals the judgment, contending the trial court erred in granting the motion. She also contends the court abused its discretion and engaged in misconduct in failing to rule on an ex parte application she had filed, requesting additional time to gather evidence to oppose the motion. We agree that the court erred in granting the motion. Hence we reverse. I. BACKGROUND To supply context for this appeal, we begin with a brief introduction to the topic of strict products liability for manufacturing and design defects. A. Strict Liability Under California law, a manufacturer is strictly liable in tort if a defect in the manufacture or design of its product is a substantial factor in causing harm to a plaintiff while the product is being used in a reasonably foreseeable way. (Soule v. General Motors (1994) 8 Cal.4th 548, 560; Johnson v. Standard Brands Paint Co. (1969) 274 Cal.App.2d 331, 337; Demara v. The Raymond Corp. (2017) 13 Cal.App.5th 545, 554 (Demara).) “A manufacturing defect exists when an item is produced in a substandard condition” (McCabe v. American Honda Motor Co. (2002) 100 Cal.App.4th 1111, 1120 (McCabe) [italics added]), such as, for example, when the product “differs from the manufacturer’s intended result or from other ostensibly identical units of the same product line.” (Barker v. Lull Engineering Co. (1978) 20 Cal.3d 413, 429 (Barker).) An example of such a defect is “the one soda bottle in ten thousand that explodes without explanation.” (Id., at p. 428.) “A design defect, in contrast, exists when the product is built in accordance with its intended specifications, but the design itself is inherently defective.” (McCabe, supra, 100 Cal.App.4th at p. 1120 [italics added].) This type of defect may be found to exist (1) “if the plaintiff establishes that the product failed to perform as safely as an ordinary consumer would expect when used in an intended or reasonably foreseeable manner” (the consumer

2 expectations test) or (2) “if the plaintiff demonstrates that the product’s design proximately caused his injury and the defendant fails to establish, in light of [certain] relevant factors, that, on balance, the benefits of the challenged design outweigh the risk of danger inherent in such design” (the risk-benefit test). (Barker, supra, 20 Cal.3d at p. 432.) The two tests are not mutually exclusive. (Demara, supra, 13 Cal.App.5th at p. 554.) Nor does one test serve as a defense to the other. (McCabe, at p. 1120.) Thus, depending on the facts and circumstances of a case, either or both may be applied (Demara, at p. 554; McCabe, at p. 1126 [“the tests are not mutually exclusive”]. In the event that both tests are applied, “[a] product may be defective under the consumer expectation test even if the benefits of the design outweigh the risks.” (McCabe, at p. 1120.) As to each of the two types of defects we have discussed (manufacturing defect and design defect), a plaintiff must establish both the existence of the defect and causation. (Demara, supra, 13 Cal.App.5th at p. 553; Dimond v. Caterpillar Tractor Co. (1976) 65 Cal.App.3d 173, 177 (Dimond).) “Expert evidence, though often relied upon, is not essential to proof of a defect. Rather, that fact may be shown by circumstantial evidence.” (Moerer v. Ford Motor Co. (1976) 57 Cal.App.3d 114, 116 (Moerer); see also Till v. Big Lots Stores, Inc. (C.D.Cal. Oct. 30, 2013, CV 12-6133-GHK (CWx) 2013 WL 12130559, *3) (Till) [“Defendants seem to suggest that a plaintiff must always enlist the testimony of a manufacturing or design expert to show that a product contained a defect. But a plaintiff can, in fact, rely exclusively on inferences from circumstantial evidence to prove the existence of a product defect;” citing cases].) So too may causation be shown by circumstantial evidence. (Camacho v. JLG Industries Inc. (2023) 93 Cal.App.5th 809, 817 (Camacho) [“[c]ausation ‘ “may logically and reasonably be inferred from the

3 circumstantial evidence” ’ ”].); Dimond, at p. 177 [“defect and proximate cause . . . may be established by circumstantial evidence”].) And courts routinely rely on such circumstantial evidence, including in instances in which a product alleged to have caused an injury is not available to inspect. (Barker, supra, 20 Cal.3d at p. 430 [“an injured plaintiff will frequently be able to demonstrate the defectiveness of a product by resort to circumstantial evidence, even when the accident itself precludes identification of the specific defect at fault”]; Hughes Tool Co. v. Max Hinrichs Seed Co. (1980) 112 Cal.App.3d 194, 201 (Hughes) [“[i]t is well settled that [a] design defect may be shown by circumstantial evidence in the event the product itself is destroyed”].) With these aspects of strict products liability in mind, we now turn to the day of the collision that led to the initiation of this lawsuit. B. Collision and Injuries On the day in issue Boos was driving home from a bar in Palm Springs, when her 2013 GM Cadillac XTS (the XTS) collided with a parked car. Several airbags deployed on impact, including a driver knee airbag located below the steering column of the XTS. According to Boos: “During the accident, my vehicle’s knee airbags deployed, causing severe injuries to my lower legs. [¶ . . . ¶] As a result of the accident, my legs were covered in deep lacerations that ran from my knees to my ankles. The skin surrounding the lacerations hardened and turned black. Several of the lacerations were so deep you could put an avocado pit inside them. The tissue and muscle surrounding several of these lacerations has never grown back, leaving what look like large, deep holes, or scoops, in my lower leg tissue. “My wounds took over four months to heal. As they healed, I noticed that the skin on and around the wounds has permanently changed in color and texture. The area of skin on and around the wounds are now covered with 4 discolored bumps. The skin also swells and, because of this, I am forced to wear compression socks. “The healing process of my leg wounds has been very painful. It frequently felt like someone poured gasoline on my legs and lit them on fire. I still have residual pain. Sometimes it feels as if someone poured acid onto a discrete, two-inch spot on my leg. Other times I will experience a deep, heavy, achy kind of pain that goes throughout my whole leg. These sensations come and go. Some days I will be afflicted by several of these painful incidents over the span of several hours. Other days, I will not experience the pains. “My legs have not felt the same since the accident. Before the accident I was very active and I walked everywhere.

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Related

Barker v. Lull Engineering Co.
573 P.2d 443 (California Supreme Court, 1978)
Soule v. General Motors Corp.
882 P.2d 298 (California Supreme Court, 1994)
Campbell v. General Motors Corp.
649 P.2d 224 (California Supreme Court, 1982)
Akers v. Kelley Co.
173 Cal. App. 3d 633 (California Court of Appeal, 1985)
Dimond v. Caterpillar Tractor Co.
65 Cal. App. 3d 173 (California Court of Appeal, 1976)
Hughes Tool Co. v. Max Hinrichs Seed Co.
112 Cal. App. 3d 194 (California Court of Appeal, 1980)
Moerer v. Ford Motor Co.
57 Cal. App. 3d 114 (California Court of Appeal, 1976)
Johnson v. Standard Brands Paint Co.
274 Cal. App. 2d 331 (California Court of Appeal, 1969)
Bresnahan v. Chrysler Corp.
76 Cal. Rptr. 2d 804 (California Court of Appeal, 1998)
McCabe v. American Honda Motor Co.
123 Cal. Rptr. 2d 303 (California Court of Appeal, 2002)
Saller v. Crown Cork & Seal Co., Inc.
187 Cal. App. 4th 1220 (California Court of Appeal, 2010)
Pruitt v. General Motors Corp.
86 Cal. Rptr. 2d 4 (California Court of Appeal, 1999)
Bresnahan v. Chrysler Corp.
32 Cal. App. 4th 1559 (California Court of Appeal, 1995)
Romine v. Johnson Controls, Inc.
224 Cal. App. 4th 990 (California Court of Appeal, 2014)
Simmons v. Superior Court of San Diego County
7 Cal. App. 5th 1113 (California Court of Appeal, 2016)
San Diego County Health & Human Services Agency v. Rodney T.
100 Cal. App. 4th 101 (California Court of Appeal, 2002)
Mansur v. Ford Motor Co.
197 Cal. App. 4th 1365 (California Court of Appeal, 2011)
Demara v. Raymond Corp.
221 Cal. Rptr. 3d 102 (California Court of Appeals, 5th District, 2017)

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Boos v. General Motors CA4/1, Counsel Stack Legal Research, https://law.counselstack.com/opinion/boos-v-general-motors-ca41-calctapp-2026.