When is an employer liable for an employee's unauthorized assistance to third parties? Sutton v. Byer Excavating, Inc. Explained

In Sutton v. Byer Excavating, Inc., the Utah Court of Appeals addressed the boundaries of vicarious liability under the doctrine of respondeat superior when an employee uses company equipment to assist an unrelated contractor.

Background and Facts

During construction of adjacent houses in Park City, Bob Miles, a trackhoe operator employed by Byer Excavating, was performing excavation work on one lot. At the request of framing superintendent E.J. Sutton, Miles stopped his assigned work to help unload rebar for an unrelated construction project on the adjacent lot using Byer Excavating’s trackhoe. During the unloading operation, the unstable rebar load struck and injured Sutton. Critically, Byer Excavating had not been hired to work on the second lot and was unaware that Miles had used company equipment to assist the other contractor until after the accident.

Key Legal Issues

The court examined whether Miles was acting within the course and scope of his employment under the three-part Birkner test: (1) whether the conduct was of the general kind the employee was employed to perform; (2) whether it occurred within the temporal and spatial boundaries of employment; and (3) whether it was motivated by serving the employer’s interest. Sutton also argued that Miles had apparent authority to perform the work.

Court’s Analysis and Holding

The court affirmed summary judgment for Byer Excavating. Regarding the first Birkner element, the court found that Miles’s conduct was not “the general kind [of work Miles was] employed to perform.” The undisputed facts established that Miles had never unloaded rebar during his seventeen years of employment, was hired specifically for excavation and earthwork, and had never before left his assigned job site to assist on unrelated projects. On apparent authority, the court held that Byer Excavating’s lack of constant supervision did not clothe Miles with authority to leave his job and assist other contractors, and Sutton failed to dispute evidence that such assistance was never authorized.

Practice Implications

This decision reinforces that vicarious liability requires strict adherence to the Birkner test elements. Employers can limit liability by clearly defining job duties and maintaining policies against unauthorized use of equipment for unrelated projects. For plaintiffs, establishing that similar unauthorized conduct was previously permitted may be crucial to defeating summary judgment. The ruling also demonstrates that apparent authority requires more than mere opportunity—it demands evidence of the principal’s conduct that would reasonably lead third parties to believe the agent was authorized to act.