Can prior negligent driving remain the proximate cause of death even if the driver later loses consciousness? State v. Lyman Explained

Background and facts

In the early afternoon of December 1, 2022, Asael Paul Lyman—an admitted alcoholic who had consumed whiskey the prior evening—drove his grandson home from kindergarten along Bangerter Highway in West Jordan. Event data from Lyman’s truck showed he entered the off-ramp at 84 miles per hour with the accelerator at 100 percent, reached 97 miles per hour before striking a concrete barrier, and then struck another vehicle at 89 miles per hour after running a red light. The other driver died at the scene. A blood draw revealed Lyman’s blood alcohol concentration was 0.12 grams—more than double the legal limit. Lyman was convicted of negligently operating a vehicle resulting in death, among other offenses, and appealed on four grounds: sufficiency of the evidence, the trial court’s refusal to give his proposed unforeseeable medical condition instruction, a prima facie speeding instruction, and exclusion of his son’s testimony.

Key legal issues

The central question was whether Lyman’s sudden loss of consciousness due to atrial fibrillation constituted an efficient intervening cause that broke the causal chain between his negligent driving and the victim’s death. A secondary question was whether the trial court erred in refusing Lyman’s proposed instruction that a person is not negligent if stricken by a sudden unforeseeable medical condition, and whether a jury instruction tracking Utah Code § 41-6a-601(3)—stating that exceeding the speed limit is prima facie evidence of unreasonable speed—unconstitutionally shifted the burden of proof.

Court’s analysis and holding

The Utah Court of Appeals affirmed on all counts. On sufficiency, the court held that the State presented adequate evidence on two independent theories: (1) Lyman never lost consciousness at all, given expert testimony that fully depressing the accelerator requires conscious effort and that steering corrections after the concrete barrier impact were inconsistent with an unconscious driver; and (2) even crediting the loss-of-consciousness theory, Lyman’s grossly negligent driving before any medical event could itself constitute the proximate cause of the victim’s death. As to the proposed jury instruction, the court found that Lyman’s requested language was an incomplete statement of the law because it ignored the possibility that prior negligent conduct remains a proximate cause even when a subsequent medical event intervenes. The court’s own intervening cause instruction adequately allowed Lyman to argue his theory. On the prima facie speeding instruction, the court acknowledged the instruction was likely erroneous under State v. Crowley because the term “prima facie” is a standard for the trial court, not the jury, and its use can create an unconstitutional mandatory presumption. Nevertheless, any error was harmless beyond a reasonable doubt given that the State never argued the presumption and its case rested on overwhelming independent evidence of negligence. Finally, exclusion of the son’s testimony about Lyman’s prior uneventful drives was upheld as within the trial court’s discretion because familiarity with the intersection was not a fact of consequence when neither party disputed that issue.

Practice implications

Practitioners litigating sudden-emergency or medical-condition defenses in criminal negligence cases must account for the proximate cause doctrine’s nuance: a sudden medical event does not automatically sever the causal chain if the defendant’s prior negligent conduct independently set the fatal sequence in motion. Defense counsel should propose instructions that address concurrent proximate causes, not merely the negation of negligence. For appellate practitioners, State v. Lyman reaffirms that statutory “prima facie evidence” language drawn directly from Utah Code is still subject to constitutional scrutiny when given as a jury instruction, but that robust independent evidence of guilt will readily satisfy the harmless beyond a reasonable doubt standard for such instructional error.