 Solution

A direct lightning strike is unnecessary. A nearby strike can produce a ground current, putting the feet at different electric potentials and driving current through the body by a step voltage. A side flash from a struck object or conduction along a contacted conductor also provides an indirect current path.^[ref]

Rapid air heating by a nearby lightning discharge also produces an expanding pressure disturbance. Its blast can impart a mechanical impulse, causing a fall or blunt injury without current passing through the person.^[ref]

The absence of a direct strike therefore does not distinguish electrical incapacity from mechanical displacement. Observations would be needed to identify the mechanism in a particular event.