As the mail carrier's errand for a friend arose from a personal motive and wasn't fairly and naturally incident to his duties, the state law presumption of acting within the scope of employment when driving a vehicle owned by the employer was sufficiently rebutted.
Although there was no written policy forbidding it, the policies incorporate managerial directives, and the manager's testimony that such a break was forbidden sufficiently supports the court's determination that the detour was unauthorized.
Driving to the store for a friend's dog food was of a sufficiently marked and decided character to take the mail carrier outside the scope of their employment. Returning to the break place did not return the carrier to the scope of employment, as the employee must return to the point of deviation or to a place where he should be located inthe performance of his duties.
Scope of employment is a threshold question under the act, and does not require jury determination as part of the merits.
https://ecf.ca8.uscourts.gov/opndir/21/08/202590P.pdf