This reminded me of an event that happened in the filming of the excellent Private Schulz.
Michael Elphick, as Schulz, and Ian Richardson, as Major Neuheim, were required to be filmed, from a distance, appearing to be on foot in the foothills of the Alps, somewhere in Austria.
It was felt that could be be done adequately in a Scottish glen, so they set off up there. Schulz and Neuheim were in full uniform and walking along one side of the valley, with the rest of the crew on the other side - by means of signals, they managed to take a few shots before a drizzly shower closed in the visibility for a while. As they waited for it to clear, sheltering under a child's pink umbrella, two hikers appeared in the distance, unable to see the film crew, because of the rain.
As the hikers approached them, they felt it necessary to speak, and possibly to offer some sort of explanation.
Then, they discovered that the hikers were actually German and seemed content to carry on as though it was a completely normal thing. Pleasantries were exchanged and the hikers went on their way.
It's a great shame that the encounter wasn't recorded on film.