Does the ending of "An Occurrence at Owl Creek Bridge" and "10 minutes" surprise you?
I assume you are refering to the short film "10 minutes" by Ahmed Imamovic. Both the short story and this incredible short film have rather surprising endings in one sense, as in the story we see that Peyton Farquhar died after all, and his escape was just a flight of fancy, and in the short film, the Japanese tourist calmly collecting his developed photos after we have seen a boy's life destroyed through the death of his family in the same time span.
On the other hand, it is also possible to see how the ending of both texts is foreshadowed at various points. In the short story, the way the landscape is described as Farquhar returns to his home indicates that something is not quite right, as we would expect him to be familiar with the landscape so close to his home:
At last he found a road which led him in what he knew to be the right direction. It was as wide and straight as a city street, yet it seemed untravelled. No fields bordered it, no dwelling anywhere. Not so much as the barking of a dog suggested human habitation. The black bodies of the trees formed a straight wall on both sides, terminating on the horizon in a point, like a diagram in a lesson in perspective.
The strange description of the setting in retrospect helps indicate that Peyton Farquhar is not really escaping, but we are seeing some strange reflection of the world in his last few dying seconds on this earth.
In the same way, in "10 minutes," the repeated references to war, guns, snipers and the danger foreshadow the tragedy that is to occur. The picture of the Japanese tourist at the beginning of the film smoking a cigarette and calmly waiting for the ten minutes also foreshadows that the film will end by returning to him. So much more can happen in ten minutes than we ever realise.