A Calgary police officer convicted twice of careless driving in connection with a 2018 collision with a jaywalking pedestrian has won his latest appeal, with the Alberta Court of King’s Bench ordering a third trial.
The case of R v Mooney, 2025 ABKB 462 (CanLII) stems from an incident on December 4, 2018, when Constable Laurence Mooney was backing an unmarked police truck into a downtown parking spot around 1:00 p.m. The truck had no backup camera. Mooney testified that he checked all mirrors, including the rear-view mirror, both before and during reversing. A pedestrian wearing a hooded sweatshirt walked behind the truck and was struck. The man fell, and the truck rolled over him. Mooney later said he believed he had hit a mound of snow near the curb. He moved the truck forward, rolling over the pedestrian a second time.
Four days later, Mooney was charged under Alberta’s Traffic Safety Act with careless driving. In October 2021, a traffic court convicted him. He successfully appealed in March 2022, and the conviction was replaced with an acquittal. The Crown appealed, and in April 2023, the Alberta Court of Appeal overturned that acquittal and sent the matter back for a new trial.
The second trial ended in November 2024 with another conviction for careless driving. The traffic commissioner concluded that Mooney had not taken all reasonable precautions, pointing in particular to a failure to perform shoulder checks before and during reversing. The commissioner also rejected Mooney’s claim that he reasonably believed he had struck snow rather than a person.
Mooney appealed again, arguing that the commissioner had applied too high a standard of care, akin to perfection, and had provided legally insufficient reasons for conviction. The Crown conceded the commissioner misstated the standard of care but argued the error worked in Mooney’s favour and did not cause a miscarriage of justice.
Justice Lisa A. Silver disagreed, finding multiple legal errors that undermined the verdict. She ruled that the commissioner had wrongly excluded relevant evidence from the analysis of the actus reus, or prohibited conduct, by refusing to consider Mooney’s testimony about the precautions he took. The commissioner incorrectly separated “objective” and “subjective” evidence and treated the due diligence defence as purely subjective, when both the actus reus and the due diligence analysis must be measured against what a reasonably prudent driver would have done in the circumstances.
Justice Silver also found that the commissioner mischaracterized the mistake of fact defence, which in law is an independent defence rather than part of due diligence. She held that the commissioner failed to assess whether Mooney’s belief about the snow was honest as well as reasonable, and improperly demanded proof of the snow’s physical properties rather than deciding on a balance of probabilities.
In addition, Justice Silver determined that the commissioner’s reasons were insufficient, failing to clearly explain how the elements of careless driving were proven beyond the fact of the collision itself. The extensive legal discussion in the decision was often irrelevant or wrong in law, and the ruling did not set out a clear factual basis for conviction.
The Crown argued the conviction should be upheld under the Criminal Code’s “curative proviso,” which allows an appeal court to preserve a conviction despite legal errors if the evidence is overwhelming or the mistakes were harmless. Justice Silver declined, citing the number and seriousness of the errors and the lack of overwhelming evidence.
Although the incident occurred more than six years ago and has now been through two trials and three appeals, Justice Silver said she had no choice but to order a third trial. She noted it would be up to the Crown to decide whether proceeding again would be in the public interest, given the lengthy procedural history.
The conviction was quashed, and the case will return to traffic court before a different commissioner for a new trial.
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